haven't seen/heard of test drive unlimited
If you're interested in a driving game - LFS (Live for Speed)...it's a driving simulator - which I highly recommend...it's still in development stages...has been for many years...but it's buyable and playable and looks good.
It's the most realistic driving game out there...you can go rally/formula 1/street...all sorts of stuff
It's a huge learning curve...and takes alot to get used to...and if you don't have a wheel or don't want a wheel - use the mouse to steer
and mountain biking is heaps of fun

i don't go as often as i used to...i busted my knee a few years back and haven't "fully" recovered...but it's almost there
