For gaming get the best video you can afford. This will be your biggest bottleneck if you plan on turning up the settings. As far as RAM get at least 1 GB of low latency RAM and run it in dual channel. This will let you run most games smoothly. If it is in your budget go for 2GB of RAM because there are some games that benefit from the extra gig. If you need more detailed advice post your specs and tell us what games you’re looking to play.
I'm running a P4 2.4 GHz, 768 Mb RAM, NVIDIA GForce FX 5200 128 MB PCI(yes, that old) video card.
This system was budget when it was bought and is pretty outdated now as you can see by the PCI vid card. I've managed to keep playing WOW and some other games by adjusting the settings and its' been fine. I'd prefer to throw a bit of money at the biggest problem and get better performance though. The best approach is probably an entirely new system but budget is an issue here.
I was going to start by buying 1 Gb of RAM but after reading the last post it sounds like that's not the best bet.
Umm... unless that system has AGP (and even if it does) it may not be worth upgrading if you want it to be relatively modern. You might look into getting a cheap PCI-Express motherboard and a relatively low end processor and possibly a mid ranged graphics card.
A budget or just "I don't want to spend more than $x" would help.
If you just want to keep playing WoW (and games like it), but just at a higher resolution and more FPS, a mid end graphics card would probably be a good solution ($100-$200). But within the next couple of years, if you want to move to large map style first person shooters (BF2, Quake Wars: Enemy Territory), then I'd go with some more RAM. The best thing in your system probably is the processor, which will still be ok until you get gfx/ram first, then the next to upgrade after that is your processor.
It might be worth buying a whole new system, just depends on how much of a budget you have and what you want from gaming.
Thanks for all of the advice. I'm either going to upgrade my graphics card, since I was hoping for an upgrade at $100-$200 or buy a new system. I checked Dell and they have pretty good systems, relative to mine at least, at their outlet starting at $350 that would get me into a dual core processor and PCI express graphics card.