Bugs I have found so far...

1. Slow resistant champions(yi in his r) when e'd into singed's w doesn't root them(Still happening even though mentioned months ago).
2. Senna's q activates glacial augment rune.
3. Double flip bug still in league and can make you an astronaut.
4. Pathing can show where enemies(if they are all in a bush together)
5. Pathing can get you stuck if an ally stands in front of you in between a tower.
6. Client crashes and instability(had me lose 3 lp because i couldn't lock in a champion in champ select). That game freeze at the last second of loading into the match also.
7. Runes when saving a half completed rune page gives you an error in champ select and (I think) changes your runepage to a complete one.
8. Riot's own website removed the technical stats of champions, but fixed the issue of stats not showing correctly by removing it.
9. Flipping champions (volibear q and singed's e) who are using abilities that target in a line auto hits yourself even if you are not in the path of the ability. This is best seen when urgot e's.
10. Sett's r can be bugged by different champs
11. minions getting stuck on tower for no reason til they die.

Probs a lot more, but this is what I have found to still be in the game so far.