My turn

Well the two-year-itch has finally arrived and I'm dying to scratch. Here are the main points of contention (discontention?) with my rig.

Intel(R) Pentium(R) 4 CPU 3.40GHz w/ HyperThreading
ASUS P5VD2-MX SE LGA 775 VIA P4M890 Micro ATX Intel Motherboard - Retail
CHAINTECH SE6600G GeForce 6600GT 128MB 128-bit GDDR3 PCI Express x16 SLI Supported Video Card
ViewSonic PF790 (19" CRT)
Linkworld 437-01-C2229 Black/ Champaign Gold Steel MicroATX Mini Tower Computer Case 430W Power Supply

Like most people right now I don't have a load of money to be throwing around so it seems pretty plain to me that I can really only look at one of these five categories for an upgrade and, personally, I'd prefer the video card be it. I've been looking at some cards out there but even without going to deep I already see a question pop up: can I use a PCIe2.0 video card on my motherboard that was available before the 2.0 spec came out? Answering that question will at least settle some issues there. I want to get something with at least 256MB of memory and DX10 compatible, if possible.

The next problem is my case. Unfortunately, I have both side panels off and a box fan in front of it doing the majority of the ventilation. It's hilariously pathetic, but it's been a common malady of computers I've built; they just run too hot, and too loud. With this particular case I have room for three case fans (front, back, side), but the side vent (which has a little tube) misses my heatsink by about an inch and I only have 1 case fan at the moment. Obviously right now, with it being winter, that's not an issue, but I can't see my computer surviving long in this state (let's just say I'm not looking forward to summer again). So if I were to get a new case I would need something that vents like a motherfucker and is quiet. I honestly don't know if anything I do will make the situation any better.

(Plus, the power supply. I'm starting to read that 430W might not be enough if I upgrade my video card or my proc/mobo. Confirm/deny?)

I'm also getting the feeling my processor could use an upgrade. This obviously means I'll need a new motherboard, which is not an exciting prospect. I want to get into newer games but at the same time I know that the further I'm going along here the less likely I'll be able to play them at any better than 800x600 with low to medium detail. That's how I'm running Left 4 Dead, for crying out loud. If I upgrade my video card, will my processor become a my bottleneck? If I upgrade my proc/mobo, will my video card be the laggard? This is why I dislike making upgrades.

If that weren't enough, my monitor is about 5 years old. Granted, it's a Viewsonic and it's a very decent monitor but it's heavy as shit and I can pick up a reasonable LCD that performs well so why not upgrade?

Any input would be appreciated. Honestly if I do any upgrading I don't want to go much beyond $200 if that. I know, it's not the kind of budget most people give themselves for a computer upgrade, but I don't want to go too crazy anyway.

Jam it back in, in the dark.