ATi vs nVidia is a personal choice really. nVidia in my opinion has the better single card configurations, but ATi has better multi-gpu configurations because it's more efficient. It's about as broad as it is wide. I prefer nVidia because I do not use multi-card configs, and I don't want to put up with ATi's poor drivers. Plus I'm a bit biased towards nVidia. As for the OT, if you don't know that much about different hardware configs, then invest into a good gaming system from either Alienware or Ibuypower. Or pay a reputable tech/engineer/computer geek to custom build you one. Be sure to get at least 8 GB of RAM, and for that price (I'm assuming 2500 euros is about 3200 american dollars) I would get the newer nVidia 480 card if you can. Get two hard drives at least, and request a raid 0 config (raid 0 makes two drives act as one, gives some performance boost). This is my two cents worth, and a lot is based on personal preference. I actually just configured an Alienware Aurora with 24 GB RAM, Geforce 295, 2.66 GHz i7, dual 1 TB hard drives for about 2100 euros (2800 american dollars). You can probably find the same system cheaper, as with Alienware you tend to pay more for the name than anything else. Id never go for alienware cause the prices are to damn high.About the RAM yh 8 GB would be good DDR3 I assume. the nVidia 480 looks great to. Now about the CPU Im not sure if I should take the i7 980x ( 6 cores ). And which mainboard and power supply would I need with it ? Id build it myself btw :)