TV series that you know you've seen every episode of.

Twin Peaks; The Sopranos; Big Love. That’s it. I’m not a mainstream TV-show guy.

**X-files

Buffy

Angel

Firefly

MASH

Battlestar Galactica

Arrested Development

30 Rock

The Office(both versions)

Extras

Veronica Mars

Supernatural

Fringe

Legend of the Seeker

Dollhouse

Wonderfalls

Pushing Daisies(including final 3)

Babylon 5

Farscape

30 Rock**

And many more…

The Venture Bros.

I’d say Black Adder, but I understand there are a couple of specials that BBC America didn’t run.

Firefly and Babylon 5 are the only ones I’m remotely confident of, having watched both on DVD after they went off the air. And honestly, I doubt there are any others.

Buffy
Firefly (yeah, that’s hard)
Queer as Folk (US)
Supernatural
Due South
Roswell
possibly Sports Night (my roommate had the DVDs and we went through 'em over a period of time; I might have missed one or two)

I have awesome taste, do not mock my love of cheesy TV shows!

Clone High, but only because it’s only 13 episodes long.

Queer as Folk
Buffy
Star Trek. All of them.
1960’s Batman
1960’s Dragnet
Soap
1970s Buck Rogers
My So-called Life
The first 4 series of The Real World

Six Feet Under
Buffy the Vampire Slayer
Dexter
Damages
Saving Grace
Lost
Gray’s Anatomy
The Tudors
Friends
Gilligan’s Island
The Brady Bunch
The Partridge Family
Saturday Night Live
The Sopranos
Murder One
Desperate housewives
Star Trek - original
deadwood
Rome
And almost certainly more that aren’t coming to mind.

Friends
FireFly
Sports Night
West Wing
Two and a Half Men
Numbers
Psych
Monk
Burn Notice
Eureka
Penn and Teller’s Bullshit
Real Time with Bill Maer

Star Trek: TOS
Star Trek: TNG
Arrested Development
Action
Buffy the Vampire Slayer
The West Wing
Middleman
Coupling (UK, of course)
Doctor Who (the revived series. I’ve also seen every existing series of the original version, but missed the lost episodes, obviously).
Turn-On
Blackadder (all four series, plus the Christmas special)
The Americans (a series about the Civil War)
Pushing Daisies (every episode so far, and I’ll catch the last three).
Babylon 5
Crusade
Nightmare Cafe (touch that dial . . . and you die!)
Masters of Science Fiction
Once a Hero (alas)
Monty Python’s Flying Circus
Do Not Adjust Your Set (all existing shows).

Wiseguy - even the Billy Dee Williams episodes and the reunion movie.

Queer as Folk
Sex and the City
Entourage
Dexter
The Office (US)
Six Feet Under
Arrested Development
Freaks and Geeks
Undeclared
IT Crowd
Lucky Louie
Rob and Big

Close:
House - seen most but missed one here and there
Had seen all of CSI until season 6, then I started getting spotty and only watched when I knew something interesting with Sara and/or Grissom was gonna happen

Even though it seems I am -always- watching TV…

Almost certainly:
House M.D.
Stargate SG-1
The Riche$
Dead Like Me

Likely:
The Simpsons
Family Guy

Probably…though a long time ago, so I might not remember them well:
I dream of Jeannie
Get Smart
Gilligan’s Island
Bewitched

Here’s my list:

The Prisoner
Gilligan’s Island
Kolchak: The Night Stalker
Love, American Style
Absolutely Fabulous
Monty Python’s Flying Circus
Star Trek TOS

That’s about all I can think of at the moment.

**Roseanne

Fresh Prince of Bel Air

Golden Girls

Frasier

Friends

Seinfeld**

(From the first few, you can tell I watch a lot of Nick at Nite, late at night while battling insomnia)

Avatar: The Last Airbender (3 seasons)
Fullmetal Alchemist (2 seasons)
Black Lagoon (1 season)
Genshiken (1 season)
Stargate: SG1 (10 seasons)
Firefly (1/2 season)

I’ll just include the longest-run series I’m sure I’ve caught every episode of:

Fraggle Rock.

All in the Family
Dick Van Dyke Show
Everybody Loves Raymond
Frazier
Golden Girls
House
I Love Lucy
Lost
M
ASH
Mary Tyler Moore Show
Monk
Monty Python
NYPD Blue
Outer Limits: TOS
Quantum Leap
Roseanne
Seinfeld
Star Trek (except Enterprise)
Twilight Zone (both series)
Will & Grace

*Hey, I’m older than most of you guys.

Battlestar (the new one), Lost, Firefly.

I’m close on The Simpons and Buffy. My wife and I started watching The Wire on DVD, and I figure I’ll add that to the list soon enough.

Off the top of my head:

Brideshead Revisited

the Office (both versions)

I, Claudius

Gilmore Girls

Sex and the city

House MD

Fawlty Towers

Futurama

Arrested Development

Dexter

Studio 60

I know there’s more, but that’s a good chunk, I assume.