Just need a computer to run some stuff. Decent games if it can. Can you guys help out

Thats going to be a hard budget to play decent games. You need a whole new system I assuming.

Yes. Check out my wish list
 

I would be afraid of that power supply, very afraid.

Its very hard to build a pc that can play games decently with a budget of 350$

You could probably do with 2GB of RAM to start with, to cut costs.  
 
The included power supply with that case will be of questionable quality (though it shouldn't be an issue if you're using integrated video). Which brings me to my next point:
 
The integrated video on that mobo will be worthless for gaming.

The problem with the rig you proposed is that it's got a weak processor, and an internal video card,
so no way in hell are you gonna be able to open a decent game let alone play it.
Please check this one out , it's can be very acceptable with almost all games, i saved up some money you paid up in the rams and the processor for the video card, which really does benefit you.
 
Linkworld 3230-18 c2228u Black Steel ATX Mid Tower Computer Case 430W Power Supply - Retail  $24.99
http://www.newegg.com/Product/Prod [...] 6811164104
 
 
Western Digital Caviar SE WD3200AAJS 320GB 7200 RPM SATA 3.0Gb/s Hard Drive - OEM  $64.99
http://www.newegg.com/Product/Prod [...] 6822136098
 
Foxconn M61PMX AM2+/AM2 NVIDIA GeForce 6100 Micro ATX AMD Motherboard - Retail $44.99
http://www.newegg.com/Product/Prod [...] 6813186142
 
AMD Athlon 64 X2 4800+ Brisbane 2.5GHz Socket AM2 65W Dual-Core Processor Model ADO4800DOBOX - Retail $60.99
http://www.newegg.com/Product/Prod [...] 6819103212
 
Foxconn 9600GT-512 GeForce 9600 GT 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Retail $119.99
http://www.newegg.com/Product/Prod [...] 6814186037
 
SUPER TALENT 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model T800UX2GC5 - Retail $39.99
http://www.newegg.com/Product/Prod [...] 6820609027
 
Total : $355.94 ,  
This is a real mid range gaming PC that could have cost alot more a few months ago
Hope you don't mind paying the extra 6 bucks
There's a total rebate of $20 if you're interested

Here's a little something I threw together, its still using the case w/ included power supply, which is certainly an issue. However, this build stays at the $350 budget and can handle *mild* gaming. (Shipping not included in budget, which will probably run around $20-25 due to shipping on case)
 
Extreme Budget Build
 
 
Linkworld 3230-18 c2228u Black Steel ATX Mid Tower Computer Case 430W Power Supply $24.99
 
GIGABYTE GA-P31-S3G LGA 775 Intel P31 ATX Intel Motherboard $64.99
 
Intel Pentium E2180 Allendale 2.0GHz 1MB L2 Cache LGA 775 65W Dual-Core Processor $69.99
 
SUPER TALENT 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory $39.99
 
Seagate Barracuda 7200.10 ST3250410AS 250GB 7200 RPM 16MB Cache SATA 3.0Gb/s Hard Drive $59.99
 
LITE-ON Black  DVD Burner $23.99
 
SAPPHIRE 100237L Radeon HD 3650 512MB $69.99
 
 
Total (without shipping): $353.93
 
IMO, this is about as much as you can do with a $350 budget. If you could add just $100 to the budget, I really think you'd have a solid entry-level gaming machine. Save up for another few weeks, sell some blood (or other bodily fluids), whatever you gotta do. Another $100 would allow you to get a better powersupply (very important) and a higher class video card.
 
I hope this helps you with your selection.

 
 
That build would outperform the one I posted due to the 9600GT. Going with AMD proc/mobo allowed the budget room for a better video card. However, I'm not so excited about the nvidia chipset microATX motherboard.
 
In the end, I still feel the buget needs to be expanded by at least $50 if not $100.
 
Regardless, it's nice to see that you can actually put together a decent little entry-level system for these prices. 2008 has been a good year for geeks 'n gamers so far.

How about if the budget is raised to 400 - anything you can do?

I'll see what I can do with 400, I'll update later this afternoon or evening.

2 good budget gaming cards
EVGA 8800GS 384 at $79.99 after rebate (close to 9600GT at lower resolutions)
http://www.newegg.com/Product/Prod [...] 6814130332
a Gigabyte HD3870 512 at $99.99 after rebate (equal to the 9600GT without AA enabled)
http://www.newegg.com/Product/Prod [...] 6814125086
Good budget  OCZ DDR2 800 RAM 2x1 GB at  $18.99 after rebate
to add to either of the 2 builds
http://www.newegg.com/Product/Prod [...] 6820227139

you can barely even get modern stuff for under 350... the operating system itself is a third of that cost.... and i wouldn't get a power supply under 50 dollars... that leaves you with like 180 to make a system... you can... but its going to be sh*t... no way you'll play "decent" games on it

Example build dependent on the rebates to make the $400 budget and doesn't include shipping or taxes
Case/PSU - $24.99
http://www.newegg.com/Product/Prod [...] 6811164104
Biostar P-31 motherboard- $59.99
http://www.newegg.com/Product/Prod [...] 6813138116
Intel core2 duo e7200 wolfdale at $129.99
http://www.newegg.com/Product/Prod [...] 6819115052
OCZ DDR2 800 2x1 GB $18.99 after rebate
http://www.newegg.com/Product/Prod [...] 6820227139
EVGA 8800GS 384 $79.99 after rebate
http://www.newegg.com/Product/Prod [...] 6814130332
HD seagate 250GB SATA $59.99  
http://www.newegg.com/Product/Prod [...] 6822148262
LiteOn DVD burner SATA $23.99  
http://www.newegg.com/Product/Prod [...] 6827106263
$398 after rebates and before shipping and taxes
 
and without an operating system unless you have one on hand already

^ exactly... you can make an ok build for 400... W/O an operating system... which makes it pointless.... so....

My suggestion is to do some careful shopping on e-bay.

Not really, there are a lot of OS out there for cheap. Heck, i have one unused in my desk drawer and so does my brother who recently upgraded/downgraded from XP to Vista. There are also some great student discounts out there. The OP can ask around with friends and family to see if anyone might have something to be used. Check out eBay or craigslist. The above system could run Crysis with a 17 inch monitor and the eye candy turned down. It's weak in the PSU department, but it's in the OPs nwer budget and a decent all around system even without any overclocking.

The op might be better off buying a system from dell, hp, etc to stay within that budget.

Good point Shadowthor, especially a refurbished system with a 90 day manufacturer warranty. Here's one at $369 with an E6550 2.3GHz and a very low