It's good on GameCube surprisingly. Plenty of hours when I first moved to Sydney playing GameCube mariokart stoned. Me and my mate used to even give it a crack and try and break each others time trial records while the other was at work or UNO.
Mario Kart on DS was decent too. We'd play 8 player through the DS connection at school during class. Was amazing.
Always Yoshi in the N64 incarnation, but I've moved on to baby characters/toad in latter versions - was not a huge fan of Double Dash but still enjoyed it, but the Wii one is really fun.