Which one is better Nvidia or ATi?

Nvidea is better for games because of speed, but anyway You can have some problem in certain games. Ati is a little bit slower than Nvidia but it will offer You more stability.Just to note that every new 3d graphic card must support directX and OpenGL as it's supported on SiS chipset motherboards. The main question is does graphic card what You are going to buy support direct 3D?

I think nvidia is more suitable because when I searched internet for drivers, well nvidia is almost every where, however ATI is also good, as a final point I will again suggest you nvidia

The two are good but if you're getting it because of games so I preferre Nvidia it has more options in open GL and in directx but for regular graphics without playing games the two are good.

I think nvidia is better..at least they sell more :)

I said .. Nvidia .. because I'm using nvidia 6100 ^_^ ....