Well, what about Ionia? They seem to qualify as more of the 'good guy' spectrum than anyone.
Still, I can see both sides, but recently in one of their in-game news things, I believe it was brought up that there was more to Noxus than met the eye. Some high-ranking official giving a speech about how they had families to feed and defend too, just like anyone else. Something like that..
Anyway, we can only see a very distant and limited 3d person perspective of the parties involved. We aren't in the diplomatic core of it, we're like citizens of a different continent reading about them in the news. I'm sure as more comes to light, the lines between 'good' and 'evil' will become blurred, and driven primarily by personal bias (primarily, I would think, favorite champions). The same goes for most of the heroes, while a few are evil for sure, most of them; even the bad ones, have some spark or potential for hidden good sides. Very human, I would like to say, if it doesn't come off as too corny.
I really enjoy the lore, and would love to see more in the future.