Not going to limit this to games I've played, but pretty much anything that's caught my eye that it occurs to me to write down.
This means if anyone wants to suggest I check out a 2D game for inclusion to this list, just provide a link in the comments and I'll check it out. Odds are if it's got something comely about it, I'll add it.
I'll try to limit these to games that have a cool artistic vision, neat effects, great music, that sort of thing, rather than every damned 2D platformer there is. I already got my XP for having a huge list, so that's not an issue anymore :)
Lotta lands and worlds in the titles, I see :)