Why not tell us about a range of systems you can buy and their prices so we can help you get the best price/performance within your budget.

my computer pulled a 360, it died on me :(
now i only have a laptop that doesn't even have a video card

I´m agree with above posts. GC isn´t that good, if you can, buy little better.

Next, about RAM. What OS do you use? If still XP 32-bit, than you have too much RAM. This system can only adress 3.25 GB.
But, in every case, I would buy faster modules. They aren´t costs that much and it´s always better to have faster.

You can't run ANY decent game? Have you tried Tetris, Doom 2, X-COM, StarCraft, Civilization 2, or Day of the Tentacle?

Everybody here is more help than me with getting your Team Fortress 2 to work. But I can offer this: http://en.wikipedia.org/wiki/List_of_open_source_games

Try www.canyourunit.com

I would get at least Core Duo E6600, Phenom X3 8600, Phenom X4 9600, Athlon X2 6000 for CPU

RAM - 2GB

VIDEO CARD - Radeon 3850, Geforce 8800 GTS

You don't want a graphics card that bad... The minimum you should be looking at is GeForce 8600 GT and even that rather low. GeForce 8800 or higher and GeForce 9600 or higher ought to be enough. Or you could go for ATI Radeon 4830 or something like that. Just... Forget the big numbers; it's usually the first two numbers that matter: the first one tells the series, the rest where it's located in the series. GeForce 8800 for example: GeForce 8, model 800 in the series. Thus, GeForce 8800. It's a bit simplified but you get the idea. Oh, and different series may not have that much of a difference (always).

Less RAM will suffice and you might even get faster RAM then. Still, 4GB @ 667 MHz is definitely good so if you find anything like that, it'll do just fine.

E7200 ought to be a good processor I think. The three I've mentioned so far are the most important components in a gaming PC. Well, naturally you should have a DVD drive :P

And in case you were to update only, you should definitely get a new graphics card (AGP slot, not PCI or PCI-E). AFAIK GF5500 is pretty bad. A GeForce 6600 GT should be good. Overclocking the processor, which you already mentioned, might be a good idea as long as you have a rough idea of what you are doing. It's rather easy though: just put a bigger FSB in BIOS, watch the temperatures and make sure it's stable (ie. doesn't crash randomly, at least more than before). Your RAM will suffice, although more would surely be better. And now that I'm talking about RAM, I must say that it's very cheap these days.

All in all, you can probably survive with your current PC if you make a couple of upgrades (should be pretty cheap, but you'll probably have to buy the parts used) but you'd still have best get a new PC.

OnLive isn't a good suggestion at this point, for we don't know if it's actually going to work or not. Besides, I thought it's going to have a monthly fee?

I'm using Windows XP and i have 1gb of ram right now. If i get a 4gb ram computer, do you recommend upgrading to Vista?

Unfortunately talking about prices wouldn't help much since i'm Brazilian and the prices here will be twisted. I'm willing to spend the necessary to have a fairly good computer for a few years

Well, i really shouldn't have said "Decent" games, because i can run Worms and AoE2, not flawless but playable

Thank you for the list, i'm trying to get into the whole PC game scene as the community seems more enjoyable

Well, i'm going to check out another PC store on monday, my friend said he got a GeForce 9600 GT and a Intel Quad 2 Corefor for a good price, what do you guys think about these?

I'm leaning towards a 8800 GTX Video Card as Zex recommended me, but i don't know if they will have it or how much it will cost. But if i can't find it, what do you guys say about the 9600 GT?

Do you think the GeForce 9600 is good enough? And what do you think about the 8800 GTX? And the Core 2 Quad processor?

I realized it's not a good idea at all to upgrade my pc by now

I have yet to take a good look at overclocking, but lowering the lifespam of my hardware is not sounding that good, but since my fellow VGCers recommend me this i need to try it

And i'm not betting my quarters on onlive. Also, the internet here in Brazil won't ever be on pair with the first world internet, so i doubt this will be of any advantage for us

"Do you think the GeForce 9600 is good enough? And what do you think about the 8800 GTX? And the Core 2 Quad processor?"

8800 GTX and Core 2 Quad should be plenty.

It depends on what games you're planning on running (I'll assume current intesive benchmark standard games), what resolution you're planning on running (on the monitor you are currently using, or are planning on buying), frame rate and quality of visuals.

Oh and most importantly, budget.

While it's not my gaming PC, I have a Q6600 running at a stock 2.4ghz (a crime as this is one of the best quads for inexpensive OC) with a 1GB 9600gt, and it plays everything but Crysis at 1680x1050 on max settings, well over 30fps at bare minimum (it's almost always much higher).

But it completely depends on the price you can get the parts for. A 9600GT at about $90 USD is a much better buy than say a 9800/8800 GTX for $180USD.  For the price difference, the performance isn't justified. At $130, the GTX is more attractive for the extra processing power, but not really necessary for anything under 1920x1200 resolution.

9600GT was a good card when I bought it a year ago, and for the current price; it's still a good card.

The Q6600 is great for OC (you will have to buy a MoBo with good OC functions with a reputation for this), but mainly from a price/performance perspective. If you're paying a premium price (or running at stock clocks), its value is diminished. Naturally, you will buy an aftermarket cooler/fan, use AS5 TIM and OC it to 3.4ghz if you want to get the most performance for your $. As far as longevity goes, you're looking at the max clock speeds you can sustain *stably* at the lowest Vcore (closest to stock as voltage exponentially increases heat) and temps (hence the aftermarket cooler and better TIM/thermal paste).

Read Tom's Hardware reviews before buying.

http://www.tomshardware.com/reviews/geforce-gtx-radeon,2218.html