Animation Cancels
A thread I saw on the boards asked if it would be more fun to play against a riven if she wasn't able to animation cancel. And this spurred me onto say something I've always thought since I joined league any back in S2.
I see animation canceling as a form of exploitation and possibly even cheating.
The ability was meant to perform in an X way. You're basically throwing that out the window and making combinations occur at a much faster than intended way. This makes champions like riven have an unfair advantage over other champions who do not posses such an ability.
They really should be patched out as bugs, it's just a smaller form of that map wide xerath bug.