What games to buy..

check indiegala.com

Farcry 1

Fable: The Lost Chapters.

Star Wars: Knights of the Old Republic.

Anything two things on this list.

Grab a bundle from somewhere as Kove said.

why not play another game from half life series? I'd say Half-Life opposing force is good old game

I suppose, really, we should ask what genres you're interested in, though all games mentioned so far have been near the top of their class in their genres.

Man you have an older computer than I do, I'm impressed.

Try XCOM: Ufo Defence, XCOM: Terror From the Deep,

Loved the games!

Fable the lost chapters.

Terraria.

Super meat boy.

I could actually play the first DoW-series games quite well on a similar PC (a little weaker one, in fact). Apart from loading times everything else was quite good.

I see you aldready have some FPS, relatively new ones, so if you like them you should try Painkiller (first one + expansion, so the Black Edition), UT2004, Doom 3, Halo, CoD2 and Serious Sam HD first and second ecounters.

1.2gb of RAM? You sir need an upgrade. I'd go with fallout 3 if your pc can handle it.

If you have the chance, try Vampire Bloodlines, and dont forget to get the unofficial patches for it, stellar game.

Planescape: Torment

Screw games! Buy universal TV remote and go piss off your neighbours!
If you do not want, check my bundle list.

Find someone who has a coupon for Recettear: an Item Shop's Tale and get it for $10.

Magicka

I would suggest getting the Max Payne bundle for $15. If you don't have them already, check out HL Opposing Force and Blue Shift.

Binding of Isaac if you don't have it. Totally forgot which bundle had it.

Also check gog.com for various older games.

Hey, if you don't know what to buy, you can throw me few bucks - I won't have that problem!

Seriously, giving any advice not knowing what you like (and the list of games you already own is not very helpful) is like firing missles and all that crap at Godzilla hoping that something eventually hit it.

Also description of your steam profile is kinda disturbing. "This is my backup account and i have gmod in this one FDG3456DFIGUESROP".

Puzzle Quest or Puzzle Quest 2 are $10 and great low memory games that can run on just about any machine. Then just pick of some of the Sega classics that are $3 each. I recommend Ecco the Dolphin.

little big adventure best old game http://www.gog.com/en/gamecard/little_big_adventure_2