Budget ($1000) Gaming Computer Rig Help

Let me start by saying it's been quite some time since I put together a computer. My current one is almost 4 years old, so I'm pretty out of touch with the latest and greatest.

In general I'm looking to put together something that I can use for everything from Crysis to WoW. I don't need to run everything on high at max resolution, although that would be nice.

The last time I did this there was a huge price drop by going down one step (or two) from top of the line, the $600 video cards were 5% faster than the $250 ones. I'm hoping that is still the case.

Anyway, I have some of the peripherals: monitor, mouse, keyboard, OS, DVD burner, speakers/headset

Technically speaking, I have the old XP install, I guess I'd need to find the 64 version or else try out vista.

My old case/PSU will be staying with my old computer for a tv-server, so I need to replace those.

I'm not too picky about sound and don't need wireless (you'd think it would go without saying, but you see people playing online games over wireless /shudder). I don't need a ton of storage space, this will be primarily for gaming, not file sharing or any other illicit activities.

Basically I'm looking for everything else, and I'd prefer that the mobo/chip come as a pre-assembled combo since it's been a while since I've done that and had one bad experience (and two fine) with it in the past.

My budget is ~$1000 USD.

Thanks in advance for any advice