Maybe I'm just a suckfor its cast, but my favorite Scorsese flim is actually The Departed. I'm not trying to knock on Goodfellas or Mean Streats or Taxi Driver, but I never tire of watching the Departed.
And by the way, Zodiac crushes Kill Bill Vol. 1. I do like the Kill Bill films, quite a bit actually, but I think Zodiac is workng on a completely different level. They'e hard to compare when you think of it.