If you had to pick any ability from any champion what would be your favourite?
I think for me it would be 
Blade Surge
Such a simple but fun ability!
applies on hit and refunds on kills, really great play making ability :)
Bard's Magical Journey is probably my top choice. Jhin's Curtain Call is a close second because it's just cool.
Hammer Form E
"B**ch, get off"
I swear I climax when I catch every squishy and a couple die before they hit the ground
Judging by the forums:
The ability to QQ about Dynamic Q.
People love that ability.
Q
There's just something about watching it become more and more devastating.
No doubts for me:
: R: Ravenous Flock
's E because its very balanced and takes lots of mechanical skill to use!
Personally it would probably be Viktor's Death Ray. Just watching it burn this line of destruction across the field is satisfying, and its very fun to cast. Jhin, Illaoi, Sion, Thresh, and Orianna have some good ones too.
Khazix's evolved E. It's just so satisfying to have that feeling of flying above the map and picking off people.
ult because COWARDS.
barrels because it's kinda hilarious when somebody goes ham on you and you've got barrels hidden everywhere and just pop one on their face and piss off.
ult because... CEASE TO BE.
wall.
best. ability. ever.
Ice Pillar, so much trolling potential towards my team; knocking my buddy playing 
whilst in the middle of using his ult out of place was never gets old.
[slayer-pantheon-rainbows]
R or W. The R is just so satisfying and makes me feel very dangerous. The shield because I love bringing that up to survive a fatal blow.
I'm trump
vroom vroom motherfucker
This is gonna be wierd but the 3rd proc on 
's W (just a really satisfying sound you know?) and tied with it is probably either Sona's ult (Dances* :3) or 
's W for the slicing sound
My own polymorph, only the enemy cast part. If you want to make sure that one enemy doesn't get to have fun, just move your cursor over that guy, and press w.
What's even funnier is when someone types on /all chat, their names become the creature's name.
Ultimate, i mean come on its the best we all know it.
His E is a close second its just fun throwing your opponents minions into his own face
I really love 
ult from a game design perspective. I don't play him a lot, and I don't even own him, but I love the idea behind this ability. It can be used for a huge number of different purposes. Peel, engage, pick, general displacement, etc. But it's not easy to do perfectly. It has a small cast time and awkward hitbox, so you have to know exactly what you're doing if you want to hit it exactly how you want it. But if you do it right, it can pretty much do anything you would want in CC.
crystallize
zone control mages FTW!
E... it's just so fun to jump into the middle of the enemy team and start wreckin faces
Fiora Q
the ability from the chat to flame until i literally caught cancer, its over in 6 months.....
Ult
ult. Most satisfying thing ever to stun all 5 enemy team members and kill the mid/adc shortly thereafter.
R
"Sing and rejoice in DEATH!"
Xerath's Arcanopulse because sometimes you just really need to poke somebody from the safety of your fountain who is recalling under their second turret.
Cutthroat because blink gapclosers are uncommon and this is the best assassin initiation skill.
Ult. Because fuck all of your mobility, that's why.
I love blink abilities like Shaco Q and Zed/Leblanc W.
I feel like they had a lot to the skill cap of a champ, along with counterplay options
Jinx Rocket. How can you not like cross map snipes AND a baron or dragon steal?
Thrill of the Hunt
Dunk
ez penta gg
Malphite's ult, when you get that 5 man knock-up [zombie-nunu-hearts]
Q is a lot of fun. He looks like a tiny fat potato, and the sight of him hopping around is hilarious.
MAGICAL JOURNEY
Just the names are Truly outrageous
