Update:
Currently ongoing:
Lost
24
Fringe
FlashForward
Desperate Housewives
Scrubs
The Apprentice (UK and US)
Dragons' Den (UK)
Cancelled or ended:
Friends
That '70s Show
King of Queens
Everybody Loves Raymond
Reunion
The O.C.
Anime:
Neon Genesis Evangelion
Code Geass
Death Note
Yu-Gi-Oh! Duel Monsters
.hack//Sign
.hack//Roots
Elfen Lied
Serial Experiments Lain
Paranoia Agent
RahXephon
The Vision of Escaflowne
Last Exile
Nadia: Secret of Blue Water
Zone of the Enders: Dolores,i
Zone of the Enders: 2167 IDOLO
Kiddy Grade
Fruits Basket
Lost Universe
Right now? I absolutely loved Southland on it's first appearance last year, and was pretty upset when it got canceled. Now that TNT picked it up for Tuesdays it's become my favorite show on the air again.
Plus the new eps will be able to have more adult content, since they have moved to a cable network like TNT. Anyone who's seen Men of a Certain Age knows that TNT can do a bit more than non cable stations insofar as content.