It's been a while since I last bought a video card(an orig. GF2 MX). Now I need to upgrade my girlfriend's machine so she can play games. The budget is max $50, so naturally I'm looking at all these diff GF2 flavors. What's the difference btw all these? I'm thinking about getting a GTS or go with a Radeon... My girlfriend's machine is a 900Mhz celeron with no plans of upgrade besides the video.