The US is where the money is, but British shows can be just as entertaining. Here is a list of all the British shows I have seen so far

Peep Show

Spaced

The Office

Mighty Boosh

Doctor Who (New)

Doctor Who (Old)

Torchwood

Robin Hood

Jekyll

Hex

IT Crowd

Red Dwarf

Extras

Hustle

Black Adder

Primeval

Black Books

Mock the Week

The Last Train

Eventual Shows: Ultimate Force, Hotel Babylon, Coupling, Jonathon Creek, Life on Mars, Spooks, Secret Diary of a Call Girl, Wire in the Blood, Moving Wallpaper, Nevermind the Buzzcocks, The Fixer, 5 Days, Kingdom, Lewis, Shameless, Wateloo Road, The Catherine Tate Show, Bad Girls,