Title. For me, it depends a lot of what champion I'm playing and my mood. If I'm playing Singed and I'm in a kinda meh mood, laning against Jax or Yasuo usually cheers me up because of how hilariously one-sided it can be. If I'm in a decent mood, Riven is surprisingly fun to fight, as is Sion.
No matter what, I love having a Vel'Koz in the game. Fun to play with, and against. In my eyes, a perfect champion.
Probably something like 
. Her laning phase isn't overbearing compared to some mids, and you know what to expect as all of her (meaningful) damage comes from the ball. It's easy to punish her when she makes mistakes; ultimately, she feels fair to play against.
I know a lot of people seem to enjoy playing vs 
but personally I get frustrated by his low cooldown, low mana cost QW spam. It gets tiresome having to sidestep that much, for me at least.
When I go mid with Talon, I just love seeing Ashe go against me mid. I know I'll snowball then.
for a lot of my toplaners, I enjoy going against 
quite a bit
in midlane, i enjoy facing the champions i enjoy playing 
and I'll always love playing against 
and 
since they hold a special place in my heart as rivals since season3
Top: 
- Ironically, that moment when you kill her because you outplayed so hard is true joy.
Mid: - Lots of room to make my own moves, and avoid hers, so I can play well to win lane through smart interaction with her Ball placements.
For me it's heavily Matchup dependant.
I love those toe on toe macthes that can swing around at any time.
When playing my main 
I enjoy to play against Immobile mages. 
I cant kill them unless I outplay them perfectly, they cant kill me unless they manage to hit a perfect combo.
Looking at the whole game not just funny macthups those champions designs I really enjoy not matter which side they're playing at:
(obviously: this works only when even in gold, when fed some of them are pure cancer! xD)
Riven and Yasou tend to be easy match ups, which I enjoy. In terms of actually having an even match up, I like Ekko and Illaoi. Strong champions where if I lose lane to them, it was my own mistake, and not something completely out of my control.
I actually like playing against 
s, I find them so damn predictable that they just feed all the time; makes me laugh :D
