Most of the ones I was going to say have been mentioned...Except Diddy Kong Racing, which in my opinion was a more entertaining kart-racing game than MarioKart 64 and had more content to it (and it looked slightly prettier as well ), even though Mario Kart 64 was still a fun and memorable game (probably better for multiplayer than Diddy Kong Racing).
The game follows a story path rather than just "cup races". There are four worlds (plus a bonus one which may be the coolest of them all which is unlocked later after enough progress) each world has four tracks and a boss to beat. You earn balloons and other important items that you need certain amounts of in order to progress for each race won, so it starts out flexible, allowing you to do things in a different order if you wish, but to really do it all by the end you really have gotta have done all the earlier stuff. You can use a different character (each with their own weight, speed and handling stats) each time you start up and enter your file to continue where you left off last time. I like the item system more than Mario Kart's as well since you have choice over what you get. In Mario Kart the items are random each time, giving you weaker ones if you are leading and better ones if you need catching up In Diddy Kong Racing you know what you'll be getting since the items are in balloons you simply just drive through and the balloons are colour-coded depending on what's inside. You can even "power up" items and get something better by getting 2 or 3 same-coloured balloons in a row before using it
I do get tempted to play it at least once or twice a year But it's too much of a hassle to bring out the N64 and plug it all in again (that is if it's even compatible with my new TV ) And because the company Rare for some reason wants nothing to do with Nintendo anymore, they never re-released it as a download for the Wii
I guess that is bothersome. Nowadays I play most of my N64 favourites on an emulator, mainly because my controllers have been severely worn down by years of constant use and it's just too painful to play some things on there anymore. I intend to replace the controllers at some point, but for console controllers N64 ones are ridiculously expensive I suppose there's the DS version, but I'm avoiding it as from what I can gather it's not really the same game.