First of all, any post along the lines of "you lie you have a cheap old dell" that isn't specifically denoted as a joke will be reported, though knowing the community there fortunately is almost no chance of that ever popping up.
Anyway, I have a Gateway FX6860-UR20P (an earlier version, not the most recent one) with 8 GB of DDR3 RAM, an Intel Core i7 Processor, and an ATI Raedon HD 5770 with 2 GB of GDDR3. This system is able to run TMUF at 250 FPS on average (unheard of just a few months ago), Team Fortress 2 at 100 FPS average, Metal Drift at about 100 FPS on average, Warhammer 40,000 Dawn of War II: Retribution at 150 FPS, and Audiosurf at 200 FPS, all on max graphics settings. I haven't tried it, but I think I could even run that unoptimized jumble of code Crysis 2 at max settings with system resources to spare.
So why, then, does Trackmania 2 cause my computer to grind almost to a halt or at least experience some sort of graphics stutter? It only really becomes a playability issue on extremely large tracks like RPGs and the like, but I can't seem to get over 50-60 FPS on the most simple tracks or even in the main menu.