IMO the game is pretty balanced and while there are a very slight few champions that I think of as not particularly good, most champions can have a role on teams especially when experimenting with different comps. In addition, there are counters to every champion that exist in this game including non-traditional counters (ignite items against mundo, pink wards vs stealth, soraka ult against a karthus, etc.). Most of the time I encounter people who are upset at the balancing of this game simply pick flavor of the month or OP champs that they consider unbeatable or play against them without understanding the champions style, kit, or damage capacity and fail to learn about all aspects of the game. Sorry for the wall of text. I just hate seeing these threads pop up OVER AND OVER AND OVER. And hey, if you don't like the game, don't give riot your money and go play something else. Neither other players nor I will ever force people to play a game they do not like.
PS: You need to look at some kittens on the internet to stop your rage