Normal games: Eve, Eve, and... Eve. especially if your team just doesnt know how to get pink wards.
also annoying team comps are also a big thing.
I've once had to go against a karma, sona, nidalee, yi, ____ (cant remember the last one). a team that just heals so you cannot push... and eventually their heals will win the game.
Also, once i had to play against a soraka, sona, tryd, ez, nasus team. Just like before...cannot push worth crap... and nas and tryd will just ult over you with soraka and sona healing. ez just kites and kils you. and if you focus ez. he just jumps behind tryd and nas.
So annoying when teams make retarded comps....