What is a solid/affordable build for a first time gaming computer?

Budget?

my computer blows right now i basically just want something up-to-date that will play SC2 and D3 smooth... the cheaper the better. just up-to-date but solid. really im looking for 500-800$ cuz i gotta buy monitor / keyboard / mouse / OS and all that too :\

Having to buy the monitor, OS, keyboard, etc. is what pushes this to the limit. This should be able to satisfy what you are looking to do.

Xigmatek ASGARD II B/B CPC-T45UC-U01 Black / Black 0.8 mm SECC / Aluminum and Aluminum Mesh Bezel ATX Mid Tower Computer Case - 39.99
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Antec EarthWatts Green EA-430D Green 430W Continuous power ATX12V v2.3 / EPS 12V 80 PLUS BRONZE Certified Active PFC Power Supply - 39.99
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Intel Core i3-2120 Processor & LG 22x Super-Multi DVD Burner Combo - 133.98
http://www.newegg.com/Product/ComboDealDetails.aspx?Ite...

ASRock H61M/U3S3 LGA 1155 Intel H61 HDMI SATA 6Gb/s USB 3.0 Micro ATX Intel Motherboard - 64.99
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

G.SKILL NS 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Desktop Memory - 22.99
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

SAPPHIRE 100315L Radeon HD 6850 1GB 256-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card with Eyefinity - 149.99
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Seagate Barracuda ST500DM002 500GB 7200 RPM 16MB Cache SATA 6.0Gb/s 3.5" Internal Hard Drive - 84.99
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

ASUS VE Series VE208T Black 20" 1600x900 5ms LED Backlight Widescreen LCD Monitor w/Speakers 250 cd/m2 ASCR 10,000,000:1 - 124.99
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Logitech MK200 Black USB Wired Slim Mouse and Keyboard Combo - 24.99
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Windows 7 64 bit - 68.99
http://www.softwaresupplygroup.com/microsoft-windows-7-...

TOTAL: $755.89 (before shipping and MIR)

wow thanks i had just picked the i3-2120. thats the farthest i got   thank you. I will have to look over. If anyone has more opinions on this it would be much appreciated  
thanks again

How about waiting till Ivy Bridge in March? Prices should be fairly low for the new i3, and you will have something as up to date as possible .

Pezcore's build looks great, except you can go cheaper on the monitor.
http://www.staples.com/HP-S2031-20-Widescreen-LCD-Monit... $80 - $25= $55

and

http://www.e-junkie.com/shop/product/473267.php $1.80 Coupon, takes $25 off that monitor.

Cool that actually works cause i wont get my tax returns till march. Your saying the i3-2120 will drop in march? or there will be a better cpu for same price?

would it make much of a different if i got 8gb of memory instead of 4? or not worth it?

If paying MSRP for the i3, then you will be getting a better CPU for the same price soon.
If getting a deal on a current i3, then you would be getting slightly less performance than
the current Ivy Bridge (rumored performance), but at a cheaper price.

I am using an i3-2100 I got for about $105 on Newegg a month or so back.

I know you're trying to squeeze the budget but I couldn't recommend an H series MB. You can get Z68 MB's in the low $100 range which will allow an upgrade to an overclockabe CPU. Most don't allow SLI but you can X-Fire a few and they do have 4 RAM slots and can accept 1600 RAM as well as having a few other amenities.
Just read this re: Ivy I3's: http://www.product-reviews.net/2012/02/16/intel-ivy-bri...
which leads me to believe that they might not appear Q2 of 2012. No mention of prices
but Tom's had a review suggesting they would be about the same as the equivalent SB's. As you can see, Singing saved $20 over the current price of an I3-2100 on Newegg so ya' gotta' look for the deals, always.

funny i was actually about to ask about that mobo.
i seen this one in another thread:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

looks nicer and its z68.
would an i3-2120 still be a good choice with this mobo and computer or would it be worth it to go i5?(there is an i5 for 189.) or would it not make to much of a difference?

and also if i do this will i have to find a bigger psu and different RAM?