I'd have to go with:
(Not on TV any longer)
The Ray Bradbury Theater
Vengeance Unlimited
Brimstone
Duckman
Millennium
Firefly
Outer Limits
Twliight Zone
Spenser for Hire
Futurama
The Norm Show
Lano & Woodley (one for our Aussie friends there

)
Various Classic UK comedies that I often rewatch - Porridge, Open All Hours, Rising Damp, Bottom, Dad's Army...and many more
(Current TV)
Psych
Monk
Burn Notice
Battlestar Galactica
Supernatural
Numb3rs
Law & Order SVU
*I just realised I watch way too much TV*