It goes like this:
Geforce3 Ti 500
Standard Geforce3
Geforce3 Ti 200
The 500 being the best, and most expensive. It all depends on just how fucking crazy you want your machine to be. If you really have 3 grand to throw down on a machine, by ALL means get a Titanium 500... also get an SB Audigy Platinum, and 5.1 Digital surround sound speakers.
Mael