Help choosing PC

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Best bet is to build it yourself or find something decent on ebay or other hardware sites like http://forums.anandtech.com/categories.aspx?catid=45&flcache=6007316&entercat=y

You are not going to find something in that price range that will play H2 well at all. You might be able to do it if you wait until the day after thanksgiving and grab as many cheap computer components as possible and build your own. But seriously,  not that possible for under $750. And if you plan at all to play any new games, you'll need to drop at least $1500. But it'll be worth it... Spore and GTA 4....

Not true. I built mine for very cheap
Motherboard + CPU= $150
Video Card= $150
250gb HD= $100
17" LCD= $100
Case= Free/$25
DVD burner= Free/$25
1gb RAM= $100    +
Total = $650

I have an AMD athlon XP 2200+ processor along with the other stuff and I can play CSS and quake 4 fine. My video card is a GeForce 6600 GT OC with dual out + HDTV. I now have 2 monitors and a TV hooked up for editing and am soon adding another hard drive for more than a half a terabyte of space.

BTW I am selling my video card because it is overkill and am getting something different.

As others have said, your best bet is to build it yourself.  Its not that hard at all, the hardest part is making sure all the components are compatible.  I've built many great gaming computers, so if you need any help picking out parts, you can PM me.