Need help for which video card to choose....

[Sigurd]

Mind you, if you've got the coin and the inclination to upgrade like that, forget about the Pentium chip and get a top of the line AMD FX series chip (FX-55 or FX-57). They destroy the Pentium chips.

I would hold off the single-core CPUs, especially with the price of over $1000 US. Even though they are great for gaming (and I hope that is not all people do on their comps.), the new dual-core CPUs would be a better choice. No game today uses the dual-core ability, but when they start doing that, bye bye single-core... AMD's X2 series or Intel's EE do better on everyday tasks and multitasks, but for now looses slightly on gaming.
Be sure to use motherboards with the right chipset for the CPUs or they will not run optimally (e.g. i955x for Intel EE dual-core with hyper threading).