One of the most fun games for me were Stunts, Re-Volt and Crashday. Any idea what these 3 racing games have in common? Track editor of course! I've spent days designing my own insane tracks and then send them to friends to drive. Or i just tried to beat my own times on them. And you never get tired of them as you can always make new ones.

There is one other racing game called Wacky Wheels. Now that was a fun game back in the day. Its pretty much a mario cart clone but it was still fun.

http://www.youtube.com/watch?v=0vVIiKp6xMs

Well there's flatout and that as legendary as you can get. I would do the Barneys pun from hymim, but I am sure every natively english speaking person is quite sick of that - reason for that is because it's legen - wait for iiiiiit - dary!

Never found Crashday to be that amazing though. Sure it was nice with the level editor, but you had to do heightmaps in a separate program and import them and more often than not you'd end up with a road banking 30 degrees and rough "bumps". Made for a tricky ride sure, but it just didn't feel fun.

I was having fun with the "campaign" level where you got to ride the tanklike thing around and just run over enough enemies in a given time.

Am I the only one who remembers Hi-Octane?

Though strangely I spent far, far more time with the demo on that game than with the full version once I got it.

Hey, you just named the game i was asking about here:
http://www.gog.com/en/forum/general/i_wish_there_were_more_legendary_racing_games/post14

This is the game i was playing at friends place and never really knew its name till this very moment. It was Hi-Octane! I loved this game back in the days.