Probably want a more powerful PSU, other than that looks like a solid build.

Yeah 400W probably won't supply enough power, opt for like 600-700ish

That should be more than enough to run TF2 and most other games at high to max quality. I have an i5-3570 and have never gotten lag in 6v6, though it occasionally would drop below 60 fps in pubs when I tried max quality. Borderlands 2 and most other games also run fine for me on high or max settings, with a worse video card (GTX 560 Ti). So you should be fine.

You might want a better power supply. 400W seems low, but I'm not sure.

Gigabyte GeForce GTX 650 OC ~120w peak power sause
Intel Core i5 3470 ~77w MAX sause

Guessing...
4 sticks of ram ~16w MAX
4 1.5tb HDD ~32w sause
other pci shit + mobo ~10w
==============================
255w@12v total system budget.

360w@12v rated @ power supply
288w counting 80+ ranking.

imo. you're cutting it close with the psu, however seasonic decided to calculate the power output of the v12 rails confuses me. You should get a psu with at least 300w@12v while considering the psu's efficiency.

Do you plan on using memory that's ddr3 1600 or greater? Do you plan on Overclocking? if yes, you'll have to get a different motherboard with the h77/z77/z68 chipset.

do not cheap out on your power supply, my power supply blew up a week ago because it was cheap.

I am not overclocking, but I guess I should get a better psu.. How many w should I get?

a 600 watt PSU from a decent brand should be perfect

GTX 650s are adorable. That's all the input I have.

I believe the 7850 radeon offers the best bang for the buck for graphics card. If you do some very simple overclocking on the Vcard you can unlock pretty massive performance with no risk, so I would favor that over nvidia.

For CPU I would really recommend i5-3570k, its around the same price as a 3470 but easy overclocking ability if you ever decide to do that in the future...and it definitely fits the "best bang for the buck" metric by far.

Power supply you can get decent 600W power supplies for around 45 bucks.
If you can be patient with your build you can snag good prices on components here:
http://slickdeals.net/

I would stick with Nvidia myself, I get screwed every time I try to go back to ATI.

And I would suggest investing in a monitor that's 120Hz, either CRT or LCD or LED. If the latter 2, then look for a very quick response time as well.

If you can possibly wing the 3570k and/or 660ti power edition, I'd recommend that. PSU is cutting it pretty close as well.

this is a budget gaming computer, 660ti is like freaking $300 for a gpu alone

Getting a psu is one of the best investments for a computer
It's really important since you don't want things to short circuit

229 for 660, 299 for 660ti power edition. 70 dollar difference for performance equal to a 670/680. If 70 dollars takes something out of the "budget" range, you should probably save more money. A 660 will be dated next year. 660ti will allow you to skip the next generation.

Of course, a new video card means a bigger power supply, but you can find a solid 600w (which can safely power a 660ti PE) for fairly cheap. Skimping on major parts to meet "budget" is foolish. Your budget should be whatever is best in a general price range, and you should save enough to match the top of that price range. Buying something now with the intention on upgrading it just means you spend significantly more money in the long run.

Get a better power supply, get atleast a 600w if its a good one or ideally an 800w ish, they arent that much but I think the 400w might have trouble with the parts ur planning on getting

Some of the sandy bridge components outweigh the new ivy bridge in temperature and other measures especially in the overclock field. I know i am a broken record but i would also use http://pcpartpicker.com for your build. You can get a good calculation of pricing as well.

http://www.extreme.outervision.com/psucalculatorlite.jsp

This is a good power supply calculator as well for you components.

OP cannot Overclock with the current motherboard he is deciding to purchase.

http://www.tomshardware.com/charts/

A pretty nice list of performance stuff to check out

400w is really pushing it on the low end. i suggest at least a solid 500w 80+ bronze at least to comfortably power your new system and anything else you wanna throw in in the future.

you'll want the 4 solid cores of the i5 for tf2, and the 660ti over the 660/650 for any other game.

i can eventually upgrade the graphics card..

...He just said you shouldn't do that and just get the 660ti.

Why would you spend 200 on a video card now and 300 later to upgrade when you could just save for a little longer and spend 300 now? How can you justify that? I don't understand the thought process of people who build saying "well in 4-5 months I'll save some more and upgrade it."

Why? Wait a month and save money.

650 = massive penile fortitude

oh and if ur gonna spend 300 bucks on a vid card, dont get the 660ti, get the 7950.

Please never ever give advice on PC hardware again.

The 660ti power edition is a much better card.

http://www.hardocp.com/article/2012/09/03/msi_gtx_660_ti_power_edition_oc_video_card_review/6

i only spent about 150 dollars on the gtx 650 ti, and i'm going to be keeping it for 1-2 years at least, i've been saving money for awhile and it isn't like i'm 20 years old and have a good paying job