For the sake of this thread, "Classic" means highly regarded.
For me, one such game is Excitebike for the NES. It's just... all you do is drive to the side, jump high up in the air, and... ummm... I'm not even sure what the goal is. Trying to score a best time, I think? It's just lame. There's no point and there's really no way to "lose." At least, not that I noticed.