Try to track down KotOR2, if you can. It's written by Chris Avellone, who's my favorite writer in the industry, and the PC version has a mod to add in all the stuff the developers didn't have time to implement.

And as somebody else said, if you already own a copy of Dragon Age then you're probably not going to get your money's worth with the PC version. You've already experienced the story and the characters and whatnot, so unless the combat being better is a huge deal to you then it's probably not worth however much you'd need to pay.

Beyond that, here:

http://www.gog.com/en/frontpage/

Nothing here will tax your computer at all since they're old games, but they're all very cheap and completely DRM-free. You can copy them for your own use as many times as you want.

I recommend:

Fallout
Fallout 2
Painkiller
Sanitarium

Just to get started. Painkiller is stupid fun, and Fallout (the first one especially) is great if you can take the time it will take to get into it.

Try Anno 1404

Fantastic, addicting game; breathtaking graphics and it's dirt cheap (£5.99)

(Tages DRM has been removed btw.)

Thanks for those recomendations, I will take a look

The Dragon Age PS3 combat really really annoyed me, so much that I just changed the difficulty to easy so I could ignore that part of the game. I would like to experience the story properly, with a different character, so I will probably try and get it cheap, but I am not going to pay above £10 for it

Anno 1404 looks interesting, what's also interesting is that it is 50 euros or £5 on amazon uk...

That being the case it might be worth it but yeah, definintely wait.

Don't feel pressured to grab PC games that will push you to the limit, either:

http://store.steampowered.com/

Be on the lookout for deals here. Never know what you'll find.

Yeah, I am using Steam more all very nice and convenient, I am just not looking forward to downloading about 100GB of games on my new PC...

That shouldn't be a problem, the games don't have to be installed. Only when you truly want to play them. So when you finish a game you could just delete the content and if you ever want to play it again download it again. the servers are very fast so it doesn't take that long.

edit: or is it the downloading itself what causes the problem???

Ben a while since I was on Steam, thanks to Windows dying on me; are you required to donlnoad as soon as you buy?

No you don't. I have about 20 games games that I have never even downloaded on Steam ever, yet.

Well, since you tried Dragon Age on the PS3, have you already played Demons Souls?   I was debating getting that one for a while but at the last minute, I changed my mind and went with Dragon Age Origins.  What's your take on DS?