TBH I enjoy the inclusion of some OP champs in the game. When I take Karthus into Zed and everyone expects me to lose and I end up stomping lane (Xiao Wei Xiao is my spirit guide) it feels so much more rewarding than if I had just picked another OP champ. I enjoy the feeling of beating someone who clearly isn't interested in really mastering the game.
I prefer the inverse of this, i'd prefer for there to be mostly balanced champions, with some very UP champions who no one would expect to win a lane or game. I use to do this all the time, before the re-releases of 
. I loved taking karma bot or mid, and completely stomping the enemy either because i have a better mastery and understanding of both champion mechanics.
The main reason for this is because it don't give people a go to flavor of the month champion, who will just mathematically win the lane, due to higher numbers.
