Input failure
Ive been playing since Noc release and this is the first time this has ever happened to me. My internet connection is stable, but in an ARAM game I was repeatedly getting a very bizarre issue where I couldn't input commands to my champion. There was no screen lag or delay on any other champion, but my own inputs would have no effect for a few seconds, and then I would be able to move/cast again for awhile.
This was happening at pretty regular intervals of 10-12 seconds, with the issue never lasting longer than 5 seconds before returning to normal.
Obviously this was frustrating, but since my connection is stable and its never happened before I feel like it might be an issue with the game itself, especially because I could always see exactly what every other champion was doing with no freezes/time lapses like you typically get with server lag.