The 3D graphics are the worst, watching the diagonal lines twist around. objects are a cube with a photo of something on them. The graphics that are drawn are much better.
You can buy a lot of good 2D modern games.
Modern 3D games look really good and manage to hide the flat polygons behind shader effects, bump mapping etc. Plus the actual poly counts are pretty insane these days.
The worst looking ones, IMO, are PC and Playstation 1/N64 etc. games from the 90's. They just haven't aged well at all, and it's weird to think we were so impressed by those 3D graphics back in the day. The textures are blurry, characters have simple triangles for noses, square hands without fingers etc. Meanwhile, 2D/isometric games from the era still look fine today.
I've been playing games since the early 90's (C64, then A1200, then PC), and I actually think now is the best time to be a gamer. The market for games is so huge that you can always find something to suit your taste. The drawback is that you have to do your research online before you buy a game, because there's so much junk out there.