Metal Gear Solid, Uncharted, Mass Effect 2, Castlevania Symphony of the Night, Indiana Jones and the Temple of Doom, Limbo and my latest "love" has to be Deus Ex, I just completed it for the first time. I knew I was onto something special after the conversation with Morpheus (the prototype A.I.), as to get to Morpheus you have to do a little exploring and then the conversation about judgement was really unexpected, even if the conversation loses it steam before the end.
Edit: The guy above me reminded me that STALKER, all of them, are also on my list.
Edit 2:...and Hitman series.