That's a pretty good budget to get a nice computer going. Tomshardware has some good budget pc guides, although none in the last few months.
I can play crysis pretty smoothly on my system (see specs), at medium settings... it plays on high, but around 10fps. I'm really good at cheap.
Black editions are nice for overclocking, but then again, so is my 4000+, and it only costs 60 bucks. I'd go with a x2 5200+ at least--those have more cache, and only cost like 115 bucks.
Take a look at anand's holiday buyers guide. It's got info on cases, power supplies and storage. http://www.anandtech.com/guides/showdoc.aspx?i=3163
I would DEFINATELY recommend the coolermaster RC690 as a case. My friend just bought that case, and I helped him switch his guts out into it, it's very nice--and very cheap.
As far as a PSU... something with modular cables would be nice eh? But that gets expensive. Right now I'm using a mushkin HP550, its not all that great, but I wanted modular cables, and it was pretty cheap when I got it on sale. Not really worth the buy at normal price though. Rosewill isn't THAT bad, my friend uses one of them shiny blue/black rosewills, and it's just fine. Try to find something with a lifetime warranty.
Optical drives... you say budget, so I wont recommend anything other than an ASUS or Samsung, from newegg... the name "liteON" kinda scares me. They are both under 40 bucks shipped.
Gskill has 2x1gb ddr2-800Mhz at newegg for less than 60 bucks.
If theres anything you want to spend a decent amount of money on, it's a monitor. You can go to the thrift store and buy a "new" used monitor for 5 bucks, every 2 months (usually gateway or dell). Or you can spend the money and get a nice samsung, or viewsonic. Acer isn't too bad.... Widescreen is the biggest scam I've ever seen, yeah 22" sounds nice, but a 22" widescreen is actually about the same size as a 19 inch regular. I don't like widescreens really at all. Some games don't even have widescreen resolutions, like "Diablo", so everything is distorted when you play--lame. But if you like widescreen, get it, I'm not gonna twist your arm too much. Spend at least $250 though, get a good monitor or you'll regret it. You gotta look at that thing all day.
Video cards.... ah yes. Try not to get one of them new 3850's or 8800GT's, unless they come with a good cooler (not the reference single slot cooler). You'll be kicking your own ass when you see the temps on them things, seriously. The bigger the fan, the quieter, generally. There is so much info out there on video cards, I feel kinda like a jerk "teaching" somebody something they already know, so i'll stop now.
Motherboards are a pain to pick out. 150 bucks will get you a nice mobo, if you are into that SLI/crossfire thing. You can get a very nice mobo though, with a single pci-x slot, for less than 80 bucks. Gigabyte or ASUS, take your pick, the rest come with junk bundles, crappy manuals, and really I've never PERSONALLY seen a bad gagabyte or asus.
Onboard sound sucks, get an x-fi xtreme gamer edition, for about 70-80 bucks. What else is there to pick from? Turtle beach....????
ya, get one of them, I dare you. Realtek onboard isn't TOO bad. Sigmatel onboard will bring you computer to it's knees while gaming, you'll think you have a virus or something, it's that bad--this is what dell gives you.
AC freezer 64 pro, or freezer 7 pro, depending on your cpu is pretty much the best cooler you can get for less than 30 bucks. I would recommend one even if you don't overclock, very nice cooler there. Other than that OCZ's Vendetta is damn nice for 35 bucks. It all depends how crazy you wanna get with OC.
Hard drives, I dunno, they are all the same pretty much
.... Depends how much "evidence" you wanna hold, lol.
As far as a keyboard and mouse go, this is all you. Logitec is very nice, as always, although I'm not a big fan of having an extra process or two, just to run your keyboard. I've never paid for a keyboard or mouse in my entire life, lol.... I'm using the dell "premium" mouse, its pretty damn nice actually, especially for $0.
You can buy an OEM version of windows from newegg, as long as you have receipts for ram/cpu/hard drive/motherboard, save a few bucks that way, Kind of a pain though. Windows is windows man, open your wallet!!!!!!!!