Visual FX Updates
Just my two cents: The game would be that much more appealing and fulfilling if at the very LEAST, Ultimate abilities are especially focused on for the best visual and sound affects. There are a lot of Ultimate in the game that I feel could look/feel more powerful or thematic so you feel like that moment actually means something, and you can see it.
Sometimes too much emphasis on 'mechanics' takes away from actually making Ultimate abilities especially appealing and thematic in just the sense of looking really cool and hard-hitting.
These are just some random ideas and examples:
Janna- Monsoon should be renamed Typhoon for it to really make sense in any other skin besides Forecast Janna. The Ultimate should have an expanding wind vortex shown with the initial knockback, and a tornado that has fx that make it scale from the ground all the way to the sky; lasting the entire channel but gradually disappearing into the grounded green healing effects. Janna would feel more powerful if she actually summoned a 'large tornado' instead of just a gust.
Morgana- The generic connecting tethers can be replaced with the effect of grasping shadowy hands that more properly fit the concept of 'Soul Shackles'.
Diana- Diana's Ultimate deserves a much cooler and more thematic fx and animation for her ultimate. She should have a row of moons that quickly come and fade along the direction she used her ultimate. It would be cool if these white-light transparent images follow an order of moon phases as its pattern.
Akali- Akali's ultimate needs a more prominent effect that occurs while 'teleporting' from one place to another. There should at least be more 'smoke effect' and maybe trace the shape of her body in addition to the 'pillar' effect of smoke and bright lights.
Leona- Leona's Ultimate would look much cooler if it came from a 'side angel' instead of just a generic blast downward, and had updated 'giant sun ray beaming down' effects.
Ahri- Ahri's Ultimate should fire fox-shaped fiery projectiles instead of generic blasts with each dash.
Tristana- The projectile her Ultimate fires really needs to be twice the size it already is and make a better 'exploding spike ball' effect upon impact that is easy to identify.
Kayle- Kayle's intervention would look thematically better if the shield was an angel-shaped or 'golden wings' aura instread of a generic shield.
Zilean- Zilean's ultimate should have a thematic and original resurrection animation instead of a generic one.
Malphite- Malphite's ultimate should have fissure/land cracking effects either across his entire path, or at least upon the impact zone. Maybe something like jagged stones popping out the ground and tremor causing the knockup force, or perhaps a small volcanic disturance with lava effects.
Fiddlesticks- Updated Ultimate Fx, more crows/crow effects.
Evelynn- Ultimate should have larger spike protrusions and a longer 'fade out' , still leaving a little lasting impression after use to make it more prominent on the map.
Brand- Ultimate projectile should be a bit more bigger/visable and have a unique shape instead of being a generic fireball that doesn't stand out or feel powerful as 'Pyroclasm' sounds. Maybe the fireball can take the shape of a snake, dragon, bird, salamander (elemental), etc.. anything to make it more interesting.
Ezreal- Updated ultimate fx to make the Ultimate feel more 'powerful' and look more like multiple attacks that travel as one.
Anivia- Aside from all of her kit needing better/updated visual effects, the ultimate in particular should look more like a blizzard (from the sky, not just flat on the ground); more wind, more snow, more chucks of ice raining down the storm that should be mighty.
Nunu- Suffers a similar problem with his Ultimate like Anivia in that the snow storm needs to look more 3D, environmental, more snow/wind effects, feel more fluent and powerful.
Kog'Maw- His Ultimate needs bigger/more powerful 'booms' when his projectiles strike the ground, maybe even making echo effects across the map in a particular radius.
Xerath- His Ultimate looks extremely underwhelming for the power he possesses. His 'seperating body' effect needs a larger, more powerful looking aura around his body that feels like it is emanating a huge amount of power. The three projectiles themselves need to look/sound more powerful. Bigger impacts sounds/visuals, larger projectiles that create taller 'energy splashes', etc.
Nami- The Tidal Wave could use updated visual effects to better simulate the fluidity of water, more 'white water splashing' at the top and ends of the wave, etc.
Nautilus- The Ultimate should look more powerful and be visually more present on the map. Higher explosions of water/earth, better colors that catch the eye but still make sense to the theme. It could also sound more 'earth-breaking' like it is a powerful environmental force.
Cassiopeia- Her Ultimate should also have visual effects that cause most of the cone area it targets to also turn into stone instead of just the enemies she hits to make it look more powerful and present.
Maokai- Ultimate should look less of a stagnant field of energy that doesn't move with the orientation of his body with weak green swirls of energy, and more into the effects of an actual 'Vengeful Maestrom'. More violent wind/leaf/arcane effects that spiral faster and look more 3D instead of flat.
Nocturne- When leaping to an enemy as the sky darkens, he should have better 'shadow energy streaming' effects and a better/powerful looking impact effect that has more darkness/shadow splashes in addition to the red icon/earth effects.
Sejuani- Ultimate really, really needs better impact visual effects. The field of frost it creates after exploding (in addition to the effects it already has) should be very noticeable and thematic, as if the explosion froze the environment as well to feel more powerful.
Syndra- The balls while using her ultimate should grow larger in size and have a more powerful audio and visual impact effect to make her feel as powerful as she dictates.
Thresh- Ultimate walls could look less generic and have a more thematic design. Perhaps chains, skulls, spikes, etc. Volibear- Ultimate should have a very loud, very cool looking purple lightning bolt effect that strikes him from the sky; a much more appealing/powerful feeling fx update. The chain lightning effect could be more vivid in fx.
Yasuo- Ultimate should have an aerial wind-current effect that his attacks leave behind in addition to the effects it already has - making it feel as if he was creating a windstorm of slashes.
Aatrox/Vladimir- The Blood/crimson effects of their ultimate could use an fx update to appear more fluid/changeable (blood-shaping into skulls, weapons, streams, siphons, etc) and/or more visually attractive/telling as powerful and deadly abilities.
Corki- When firing the more powerful missles during his Ultimate spamming, the powerful missles should have more powerful exploding effects, louder/more powerful impact noises, and maybe move in a slightly different way than the regular missile (without affecting mechanics).
Jarvan- Really needs updated Ultimate fx, where the Cataclysm wall actually looks like a wall, 'terraformed' into something that better resembles a sturdy arena.
Gragas- Ultimate needs better/updated 3D splash effects from the explosion, where it isn't just a grounded flood of wine but has more of a fluid/fizz splash effect.
Graves- The Ultimate projectile should look more like a exposive shell; the explosion effects and the impact sound needs to look more powerful.
Kennen- Slicing Maestrom should look less like a flat, stagnant aura field and more of a moving force of electrical energy or static force, while improved effects of lightning bolts rain down from scaling all the way from the sky as they strike enemies.
Amumu- Ultimate aura can use an fx update and a more thematic sound effect. Better effects that visualize enemies being wrapped by bandages. Maybe the bandages can also sprawl out from the ground in an eerie random pattern as an environmental effect.
Braum- The Ultimate could use an icy fissure with larger protrusions left with the animation and effect, and a bigger impact 'bang'.
Caitlyn- Could use updated visual effects that causes the bullet she fires to look more sniper-like, and the targeting light a red line by default.
Shaco- The 'blade exposion' effect of the clone could be updated, more 3D and visually appealing and more deadlier/dangerous looking.
Shyvana- Dragon's Descent first should look more like a dragon, and the initial leap should have a much more powerful looking fiery entrail effect. She's going to get updated in any case.
Orianna- Ultimate really needs better visual effects to make the 'shockwave' force brighter, louder and more powerful feeling. Skarner- Entire body should glow a brilliant light blue aura of crystal light as he suppresses a target as if he is focusing a great deal of power upon one subject.
Alistar- Ultimate effect could look less of an aura of floating shields, and maybe be more thematic. Growing a larger size, causing vivid effects of cracking earth underneath his feet with each step, having the orange aura below his feet normally instead surround his entire body in an aura, etc..
Rumble- Updated Ultimate effects that cause the missiles sticking in the ground from different angles and have an explosion effect upon impact - instead of a linear, boring line of non-interesting missiles.
Trundle- Ultimate could be more noticeable and prominent in effects with brighter effects between himself and the target he is absorbing heat from. Maybe even a transparent thematic 'tether' to show who Trundle has currently used his ultimate upon during its duration. Visible to only himself and the target, etc..
Veigar- Ultimate projectile should start big, and have updated thematic affects to be less of a generic projectile of energy with a tamed explosion, and a more devastating dark energy force that hits with a bigger bang and energy explosion effects upon impact.
Swain- Ultimate could be reworked visually so he literally becomes a larger 'raven-man' that looks less human, more deviant and demonic, etc.
Lucian- Ultimate projectiles upon impact should create brighter flashes of impact.
Jinx- Missile explosion should be louder and 'taller', and the happy face/aftermath affect should linger on the ground much longer before fading.
Kassadin- The 'rift' effects that occur teleporting from one place to another should be a bit brighter and more defined, while having effects with much slower fading times to let an impression remain.
Hecarim- Spectral soldiers could be more vivid, brighter and visual within the Ultimate's effect.
Sona- Ultimate could be visually brighter and flashier, perhaps with more pronounced 'soundwave' affects and maybe musical notes/symbols of that golden light trail off like an aura along with the basic affects to make the struck chord feel louder and more powerful.
Soraka- Brighter ultimate affects to make the heaven light fall from the sky with more vivid color.
Victor- Ultimate needs updated effects to make the Singularity look less of a device projecting weak lightning animations while the area of effect remains flat on the ground, and more of an actual device being the center of a large ball 'chaos storm' with 3D lightning and gravitational alternation effects that appear much more powerful and vivid; a threatening force.
Rammus- Ultimate effects could be made more vivid, loud and powerful in theme of causing a continuous tremor around himself that cause echoing rumbles and more disturbed earth in addition to its original effects.
Kalista- Ultimate could use longer lasting tethering, recalling, impact, etc effects that fit thematically and don't go along as virtually invisible.
Karthus- More powerful 'energy from the sky' effects, bigger explosions and louder impact sounds that feel much more powerful and hard-hitting.
Jayce- The first attacks he uses after switching weapons really need more powerful/updated impact effects that stand out.
Irelia- The Ultimate might look cooler if instead of the spirit blades floating behind her the entire time, they very quickly fly around her like an aura until fired one by one to make them look more dangerous. The spirit blades could also be a bit bigger and updated in look.
Any ideas of your own/things you'd like to personally see?