Green Acres - Dadaism in a box
Johnny Carson _ Cavett was good too
Mash - Especially the original cast
Barney Miller - Best ensemble comedy ever
WKRP - Big Guy: "As God is my witness, I thought turkeys could fly"
Taxi - The funniest scene on any show ever - Louie and the Girl Scout
Soap - If you hated soap operas you loved Soap & rightwingers hated it
Mary Hartman, Mary Hartman - Like Soap but more working class
Pushing Daisies - literate quirky comedy, victim of writer's strike
Twilight Zone - Very imaginitive
Maverick - Garner was just cool
Rockford Files - Ditto
Monk - Tony Shalhoub is funny but premise starting to wear thin
House - Currently the best show on Network TV

Lot's of good stuff on PBS: Antiques Roadshow, American Masters (really good one about Garrison Keillor recently), BBC Mysteries (Inspector Morse was my all time favorite and the recent ones with Kenneth Brannagh playing a Swedish detective were quite good).
Which brings me to the absolutely greatest thing I've ever scene on Television, also on PBS: the 22 hour 8 night long Civil War documentary by Ken Burns. Just incredible.