It's impossible to perfectly balance a game like this. There are too many variables to consider. The game needs to be at the very least tolerable/bearable. Right now LoL is EXTREMELY unbearable to play balance wise. The disparity between champions is unreal. An S tier champ is leagues above an A tier champ (no pun intended) and uncomparable to a B tier champ.
What are some examples of those S & B tier champs for you?