The most well designed champion of each class.
Here are the champions who I think that each champ in their class should aspire to be like because they define the class well and are very well designed, at least, relative to the class they're in. Many of these picks will be very controversial and you, yes you, will most likely disagree with most, if not all of them. But I'd like to think most of my reasoning is fairly stable c:
Mages
I'll start with the hardest one, because there are so many well-designed mages. But I think the one that takes the cake for who I think has the best design is 
. She has 0 mobility in her kit, but she has fairly good poke, okay CC, and decent burst. Everything a mage should have. And she's fairly skill-oriented. No matter what the preconceived notion about Syndra is, she can't just press R and one shot. She needs to set it up with her Q's first, then press R. It's not much, but it's something. Also her R doesn't have to be used for burst. It can be used to place a ton of balls, then have a massive AOE stun. (Saw this in a pro game once by Faker, I'm still shook from it). And while Syndra can be overbearing in some metas, I don't really ever recall her being overly underpowered, unless every mage is underpowered as well.
Assassins
This one isn't very hard because there's so many stupid assassins that I can eliminate almost instantly. The 2 assassins I just considered are Zed and Kha'Zix, but the one that I decided was 
. The skill expression in his kit isn't super high, but he is squishy, has some mobility, some stealth, and burst, things every assassin should have. The great thing about Kha'Zix, though, is his burst is significantly less strong if his opponents aren't isolated. I love this mechanic because it just screams Assassin. He jumps into a lone squishy, bursts them, and jumps out. But if the squishy isn't alone, he gets wrecked because he can't get his burst off right. That one mechanic is what brings Kha'Zix to the top for me, even if in some metas he can be very overpowered, he's generally not too overbearing.
Tanks
This one was pretty easy for me, but a lot of people will probably disagree with me because he was given the Ryze treatment. Ever since the trailer for 
came out, I knew he'd be my favorite tank. They messed him up a little bit, but he doesn't have much competition. He may be the most skill-oriented tank because everything he has is a skill-shot, and most of it is fairly short range. He has little reliable poke (which is something I hate on tanks) and not very reliable CC. In order to hit his major CC (his E) he either has to position his Q really well, or rely on a misplay on the enemy's part by walking too close to a wall or something. And his R is, while being fairly difficult to land, is very rewarding when you do. It is one of the most powerful ultimates in the game, and is honestly just super cool.
Marksmen/ADC's
Holy shit this is hard.. Along with mages I think ADC's are the next best designed champions. I put a lot of thought into this one, and the one I decided to go with, from an entirely objective standpoint, is 
. There are several other ADC's who could easily take this spot, but here's my reasoning. Jinx has high damage, low mobility, and a little bit of utility. The way her Q can change her from poke to farming to poke to farming is really good for an ADC to have IMO, her W is a really nice poke/kiting tool, her E offers some hard to hit, but rather rewarding CC, which is something champs that almost made it like Kog'Maw and Sivir don't have. And her R doesn't need much explaining. It's a finisher, a cross map snipe, can steal objectives, and is really fun to play with.
Enchanters
This one was essentially between Janna and Nami, but I decided to go with 
. She just has the most skill expression out of all of the enchanters (if you're not counting Rakan, which many people don't). Janna's Q is designed in a very smart way, so the player really has to plan to hit it right. Her W is just a standard point-and-click poke with a slow and shit, and her shield, again, pretty standard. Where Janna shines is in her R. It's one of the best disengage tools in the game, and can work offensively if the Janna player is really good. The plays that can be made with this ability simply clear out the competition of other enchanters because it's just so fucking cool, not that there's stiff competition anyway.
Fighters
I was somewhat hesitant to put this on the list just because 'Fighters' can be classed in so many ways, but this just includes fighters, bruisers, etc. Ya know. The one I chose from this large list of champions is 
. Jarvan really is rarely super overbearing but is never really weak either. I really like his flag and drag mechanic, I like the whole "2 abilities that are nothing alone but something together" is pretty cool, and it can lead to some cool plays. His ultimate is like a more balanced version of Camille's, in the way that it can be escaped, but usually you need something like flash to get out, because if he uses it he's generally burned any other mobility spells. I find it weird how he gets some seemingly very random skins (Dark Star, Hextech, I see no reason for these, especially when he got SSG, he's really not that popular) but I guess I don't mind. I think he's pretty well designed overall.
I think those are all of the main classes. Now, these aren't my favorite champions of each class by any means, they're just who I believe to be some of the most well-designed champions in these classes. If you read through all of those, you probably think I'm a fucking idiot in one way or another, and if that's the case, feel free to yell at me in the comments. I'll probably follow this up with a "worst designed champions for each class" list at some point, we'll see.
(now that the fast is gone)
just due to amount of sheer counterplay which his axes have. No other adc is close to him when it comes to relevant counterplay
etc. are pure statchecks without any relevant counterplay. Draven can bully people, but counterplay to him is really clear and satisfying for both parties. Find me any other adc with counterplay other than "burst them" and "stay outside of their range"
and a 
and she will instantly lose a lot of steam, i tried it on shyv and it worked great enough.
or here 
or even here 
Flashy without feeling overloaded or unfair (i.e 
)
Similar to Ahri, her kit is easy to understand but has a lot of room for execution. Doesn't ever feel unfair. Points for cuteness.
.
similar to Katarina, also extremely fun and cohesive to play.
are probably the top 5 best designed mages.
Gonna show my bias on this one, since I'm a Shaco main, but hear me out. Shaco is one of those champions who is loved by his mains and despised by everyone else. His kit is absurdly strong in the right hands, he's notorious for abusing items, his playstyle frustrates players to no end, and he snowballs harder than any other champion in the game. Despite these faults, I believe a meta where Shaco is strong (but not TOO strong) can serve to teach players a lot about the game itself. Shaco does one thing, and he does it well: he punishes mistakes. His abilities allow him to wreak havoc on disorganized, uncoordinated teams, and on players who lack the game knowledge to play against him. I don't mean to offend anyone by saying this, but it's a simple fact that Shaco thrives in situations where players are inexperienced. To play against Shaco requires an entirely different set of skills than what your average player is used to. Because of the simplicity of his kit, a greater burden of knowledge is placed on one's strategic aptitude and the ability to think in unfamiliar terms. A good example of this is warding. Warding against a Shaco is completely different than warding against other junglers because there are a lot more places Shaco can gank from. Thus, it is more effective to ward Shaco's camps rather than lane bushes. Knowledge of jungle routes is important in predicting where Shaco might show up next. Playing against Shaco requires you to plan your moves carefully so that you can foresee in advance where he will be and act accordingly. In essence, you must put yourself into the mind of the Shaco player. And this is why Shaco is such a joy to play against. It's a battle of wills, a meeting of minds; one person's strategy and tactics vs. another's. Much different from the usual mechanical outplays that people are used to making. Shaco draws people out of their comfort zone and forces them to adapt to unique situations more so than any other champion in the game. Every time I play against Shaco I learn something new about the game, or I play the game in a way entirely different from the way I usually do.
Gonna keep this one short and sweet since I know the least about the ADC role, but Ashe is basically the most balanced ADC in the game. Even if she gets incredibly fed, there's always a way to take her down. Ashe is a very unforgiving champion to play as, and this means that Ashe lanes are typically more about an ADC's relative skill than anything else. She doesn't have any bullshit safety mechanics like Tristana, she doesn't have absurd burst damage like Xayah or Draven, and she doesn't have any way to turn the tables if she messes up like Vayne. She's a pure ADC, one of the last there is. Playing against Ashe, you never feel like the game is hopelessly over if she's fed, and in this meta that means something.
I'm gonna preface this by saying Bard IN HIS CURRENT STATE is not my ideal Bard. He simply does too much damage right now (but then, who doesn't?). For this pick to be valid, damage creep would have to be scaled back; think Bard how he was 2 years ago. Anyway, Bard is a champion that I feel doesn't get enough credit. I've seen Bard players pull off amazing things, and anyone who can play this champion well has my full respect. Playing against Bard is just so damn entertaining that I can't justify giving this spot to anyone else. He can do things that no other support in the game can, but at first glance his abilities belie his potential. Bard games are great because they force people to get creative with how they use their champion. His original intended purpose as a roaming support was, at the time, something entirely unheard of when it came to champion concepts. A good support would, of course, roam to other lanes when the opportunity presented itself, but Bard is the first example of a support designed with roaming as a major focus of his playstyle. As I mentioned in my Shaco example, anything that forces players out of their comfort zone to experiment with new ways to play the game is a good thing in my book. Adaptability is key when it comes to playing Bard, and it's also important when playing against Bard, because there are so many ways he can aid his team.