Building a new computer, need help

[winterfreshpwnz]

Hey guys, I haven't been on this site in forever and my last computer was a socket 939, literally when SLI had just come out. I have been completely out of the computer loop for years and although I have done a little research in the past few days, I am stil pretty clueless with all this AM3, DDR3, and six core nonsense lol. I honestly just want a midrange computer because I won't be doing anythign intense on the computer and like I said, I've been out of the loop and that means the gaming loop as well so I will be mostly playing CS: Source. I basically just need a mid-range system for no more than maybe 600? But at the same time, I want it to at least last me a few years like my old computer did. Any suggestions are greatly appreciated and feel free to ask me anything. Thanks.

edit: I forgot to mention that I want to go with an AMD setup.

Really? You guys are that lame? If this was five years ago, twenty people would have responded by now. All I'm asking is for some suggestions....