strangely, my number one pick for best cycle game is SUZUKI TT SUPERBIKE on the PS2. I like it because it is smooth, fast, and reminds me a LOT of riding on real live streets. It is the fully reproduced ISLE OF MANN TT race track... reproduced corner for corner, bump for bump, has a boat load of fine street and race bikes, and once you get used to it, I feel the handling, feel, physics and control is better than Tourist Trophy [which I also own]
Other decent* cycling games: [*according to gamerankings.com]
XBOX 360 - MotoGP 06
XBOX - MotoGP, GP2, GP3,
Speed Kings <- arcadey street riding
PS2: - MotoGP, GP2, GP3, GP4
Tourist Trophy
Suzuki TT Superbikes
Speed Kings
Riding Spirits - reviews not Super, but I read there's a busa in it? ? maybe
PS1 - MotoRacer, MotoRacer2, MotoRacer3
Ducati World Racing [yeech!]
Superbike 2000
Honda Superbike
GameCube - SpeedKings - has a fake Busa in it
Dreamcast - Suzuki Alstare Extreme Racing
And for the PC - there are a bunch of great Demos to keep you riding free!
MotoGP, 2, 3
MotoRacer, 2, 3
Midnight Club 2 - has a bike in it, but it's a car game
EA's Superbike series - good luck getting it run
Ducati World Racing - again, bleaah, very badly done, but runs on an old laptop if needed
there's a bunch of other piddly games strown about, but you will never find them, or they won't run at all on modern PCs.
I suggest you grab MotoGP 3 Demo and have a ball, like I am seen doing here