[Vampyr]

What is keeping you from building your own again? It will be cheaper and more than likely better.

However, between the two you mentioned, I would definitely go with a Dell. I have had horrible experiences with HP, and it seems like most people I talk to have as well.

On the other hand I've had several Dell's, and not had any issues with any of them, up until they were so old that it couldn't really be helped.

As for the number of cores - go with a dual core. A quad core is going to be more expensive, and it will actually hurt your performance. The reason is because each individual core of the quad core is slower than the dual core, and you are probably not going to be doing anything that is going to be able to make use of those extra cores. What this means is that you'll be running most of you programs on 1 or 2 cores anyway...so go with the one with fewer cores that each have a higher clock speed.

Also get at least 4 gigs of RAM.

If you are going to be playing games on it, get a video card with 512 MB of memory.

Disclaimer: I work for Dell.