I've been playing the first 3 tomb raiders lately and I like how it rewards you for exploring the levels. I want to know if there's more like it.

Detailed as in graphics, or detailed as in most developed and detail-rich setting? If the latter I'd have to say Planescape: Torment.

ChiliDragon

I'm not sure, but i like the detail in gta 4 as in theres alot virtual websites to read just for fun and the little details like how every car's engine has a different model. I just like neat little things like that.

What is the most detailed game world you've ever been in on a pc game?