Can you really go wrong with this? Why aren’t you downloading it now? Free online/lan Trackmania Nations Internet/Lan game for your PC, it has over 90 tracks (ok some are only 30 seconds long, but most of them are "normal length"). If you get bored of the massive amount of tracks in the game, just make your own with the free build in track editor:

Trackmania Nations ESWC edition is a fast-paced racing game involving precision and agility specially designed for competition in partnership with Electronic Sports World Cup and free for download. It’s a high octane, free wheeling game of insanity where players can construct totally original tracks with gigantic jumps, loops and high-speed corners.

Download it from one of these fine mirrors:
– 3D Gamers
– Gamers Hell
– Nvidia Zone
– Worth Playing

And if the ability to download some free gaming goodness doesn’t quite grab you, look at these Trackmania Sunrise screenshots that give you an idea of what to expect.