Some of them can be a bit valuable.
I mena, I love my N64, however a lot of games in that era don't hold up that well. That early 3D stuff can be pretty rough around the edges. There are stand-outs, Super Mario 64 for example, but some just weren't quite there. Like early Tomb Raider or Resident Evil - they didn't really hit their stride until the next console generation, when the power caught up to the vision.