I much preferred Thief II to the others. The Dark Project, while fun, lacked a lot of the feeling of being a thief since half the time you fought off monsters, and Deadly Shadows didn't feel right, though I liked the expanded City.

The Metal Age was nice because it focused on more human opponents and areas, while still switching it up with the Servants and such. It just felt more like you were an actual thief out on the prowl. Plus I liked Karras and Truart as villains more than The Hag or The Trickster.

My favorite level was "Robbing the Cradle" from DS though, definitely.