The only ones I've played recently are Mass Effect 1 & 2 and GTA 4. I'm not big on 3rd person games. Other than those three I've played Star Wars: Knights of the Old Republic 1 & 2. That's it.
Those Star Wars are old games and are not officially supported by Windows 7. I believe there is an hack for them so you can play in Win 7.
I highly recommend Mass Effect though if you have not played it. It has a very good storyline which is a reason why I bought and BioWare is known for making excellent RGPs.
BioWare also developed the Star Wars: Knights of the Old Republic 1 (KOTOR 2 was developed by Obsidian), but the controls are a bit quirky compared to Mass Effect. Not surprising since BioWare had a long time to refine the controls.
I am contemplating Dragon Age: Origins (2009) because it has received good reviews and it is another RPG developed by BioWare so I'm pretty sure I will give this 3rd person game a shot.
Dead Space 1 and 2! One of the best Third Persons's AND its a horror series! Also, Max Payne 1 and 2 are good oldies. Splinter Cell: Conviction...great stealth play!
Also Kingdoms of Amalur: Reckoning. If you liked Baldur's Gate and Champions of Norrath, this is your game. There's a PC demo if you want to try it out first. (Though if you have a Radeon card you'll need to force at least 2x MSAA in CCC to play the demo on all high settings.)