One major gamebreaking "feature": Abilities being cast through CC
**Queued abilities are being cast through CC. **This has been ingame since the orginal release of the game - and now it's more frustrating than ever. E.g. enemies that are standing in a Soraka silence field and still manage to use an ability. Enemies standing in Cassiopeia W dash out of it.... The same goes for all sorts of stuns.
It's simply incredibly frustrating to die because of this "feature", you see the stun animation above your enemy's head just to die to one of his abilities.
(This bug frequently happens when abilities are cast during a small timeframe. The game has a HUGE tolerance window for when you see that your opponent is CC'd - and the point of time where it at actually stops him from taking action)
It'ld be a big gameplay change to lower the tolence window - but I believe that it'ld lead to much less frustration.
EDIT: Since I was asked - my ping is constant 18~24ms.