As of now I currently have a Dell Studio XPS 435MT with the Intel core I7 920 @2.67 ghz, 6gb's of 1333mhz ddr2 RAM ( I think ), an NVidia GT 220, and I just swapped the stock 360 watt PSU with a Corsair 500w. What graphics card should I upgrade to for better visuals in gaming like Flight Simulator, BF, and COD but at the same time not burn everything up?