Am I the only one who can't help but adore the Episode 1: Racer game for the 64?
Granted it's not a fantastic game by any means, but I would think I'd hear people mention it more. It's probobly within the top ten in my 64 collection, but then again I'm missing a few games (Banjo games, Ogre Battle, Smash Brothers, any and all Mario titles sans Mario 64).
It had a great sense of speed and some excellent tracks. Not to mention a fairly hefty upgrade system that made for good competition against siblings. "My Pod Racer is faster than yours! ZOOM!"