Vampire the Mascuerade - Very well made scenerier, intrigues and characters. Besides, I love the world of darkness and vampire theme.
Starcraft - Blizzard has amazing skills in programming and graphics.
World of Warcraft - Well, it was entertaining for a while, but then I lost interest after level 42.
Gothic I & II - Characters and Storyline are well written and the game interface intuitive and innovative. There is a part 3 that I haven't played yet.
Sid Meiers Pirates! - Retro, yes, but still going strong.
Heroes of Might & Magic, and the Might & Magic RPG series - What can I say, I just liked them.