The best purchase has been my old Creative Labs 3D Blaster 3Dfx Voodoo Banshee 16MB AGP. It lasted working OCed about a 10% (don't remember the right speeds) from 01/99 to 09/03 and with tweaked drivers it still had a nice performance by the moment of it's retirement (welll, at 800x600 on my 15" screen wich was the highest trully useable resolution).