Thief: The Dark Project
Its emphasis on stealth, strategy, and ingenuity, coupled with its strong narrative structure and excellent mission design, adds up to a game that's stylish, serious, rewarding, and unique.
Blade of Darkness
It's got some problems and takes some time to get into, but should otherwise appeal to players who've enjoyed previous hack-and-slash action games, or like the idea of them.
Thief II: The Metal Age
The mission design is more consistent than the original's, and some of the missions are among the best in any action game to date.