Test Drive Unlimited for me was a bittersweet experience, while i enjoyed the graphics (which requires some hefty horsepower to view all the goodies) and the number of cars the lack of focus and an overlying goal kept the game from staying that long on my hdd. here's IGN's take on the game:

Test Drive Unlimited brings so many things to the table that we've been waiting forever to be included in a racing game. From the fact that the entire game world is essentially a lobby for multiplayer gaming to real-world open ended racing, Test Drive Unlimited gives you the option to let your imagination set the course. The game successfully brings the feel of the MMO world to the racing genre making for a unique game. The driving itself isn't the best around, especially when you get on a motorcycle. Just the way that an MMORPG can be enjoyable without an amazing combat system, Test Drive Unlimited is fun without the greatest driving experience.