Anything HBO throw money at is almost always brilliant TV.
From what i've seen:
Entertainment - 24 (stay well clear of Season 6) Prison Break (don't go past the first Season) Spartacus: Blood and Sand
Sci Fi - Twin Peaks
Writing - Deadwood, The Sopranos, The Wire, Boardwalk Empire
Anime - Cowbody Bebop, Monster, Ghost In The Shell
Comedy/Smoking Weed - South Park