So, if I can buy another computer, should I, and what? Need advice

I'm lifting the ban on Mac-lovers :-) Sony just shipped the new hard-drive to try out and see if that's the problem. On the other hand, Amazon just wrote me (I know, they're R-lovers, but I bought this two months ago before I knew that) and said that they'll take my computer back and refund me, if I like. So now I have a dilemma and need advice from you computer geeks.

Basically, I'm obviously still a bit worried that this computer has never quite acted right since I got it. But I'm wondering, having spent around $1100 on the tower, is there something else out there I should get instead? I.e., take the Amazon refund, send the 'puter back, and get something else?

I'll tell you my interest in getting the computer that I did. It's a Sony VAIO RS-720G desktop. I wanted a desktop because I've always had laptops and finally wanted something powerful, with a big-ass screen (bought a 19 inch screen I'm keeping). The specs that I like about this computer are:

- 200 gig hard drive
- Ram expandable to 2 gigs (comes with 512)
- Pentium 4 processor, 3.0 Ghz
- 7 USB 2.0 ports
- built-in readers for various memory, compact flash, sony memory sticks, etc.
- Coaxial cable input and already has sony's gigapocket software so I can ouput my tivo to my computer, and burn it on my computer

Basically, I want a fast computer, good with games, that I can use for regular word processing, Internet, etc., but also for creating and editing photography and video (for fun and for my political work, the blog, etc.)

I want some serious advice as to whether and what I should spend the $1100 from the tower on instead, if I should at all. I'd like to keep the 19 inch screen, I love it . So, do I consider a Mac, if so what? Can I get another tower cheaper and just as good, and if so, where? Brand recommended?

Thanks as always, and I consider this an opportunity for the rest of you to see what the best advice is out there since most of us will be buying a new computer, whether for ourselves or someone else, sometime in the next year or so.,