Just another new build thread ($1000)

Here we go. My laptop just went the way of the dinosaurs, so it's time for a desktop. I don't have a monitor so that is included in the build. I would be using this rig for a wide range of games and I do not need to be playing them at max resolution or max settings, but higher is always better... Here is what I am looking at so far, please feel free to suggest specific brands and models, as this is very early in the thought process! By the way, I am shooting for about $1000 (some of my money and hopefully some Christmas funding). I had a 3 year old Gateway M680, thus all of this is going to be a more than modest upgrade.

Monitor: 20'' widescreen 1680x1050
Case: Mid-tower (I have no idea what brand)
PSU: 550W or maybe a little higher
Mobo: No clue, not in need of crossfire or anything like that. I would be more likely to upgrade to a new mobo in a few years to take advantage of newer cpu architectures than to upgrade by adding another video card.
CPU: Something dual core. AMD 64 x2 6000 or 6400. Intel seems to be so much more expensive but worth it from what I have been reading. Maybe a Core 2 Duo E8200 or E8400. How important is 45nm vs 65nm?
Memory: 2GB DDR2 PC2-6400, I was shocked at how cheap memory has become.
Gfx Card: ATI 4670 or 4850, Nvidia 9600 GT or 9800 GT depending on prices.

I think the rest I can do myself (optical drive, hard drive, keyboard, cooling fans, etc = sub $130). Thanks in advance to anyone who responds. I am most interested to see opinions on motherboard/cpu and monitors.