“Welcome Back Kotter” had a great little ditty that just about anybody could sing along with, even with a rubber hose up your nose…
My favorites in no particular order:
Underdog
Secret Agent Man
Ultra Man
Friends
Batman
Twilight Zone
Green Hornet
Lone Ranger
“Five O’Clock World” from Drew Carey
Peter Gunn
The Original Spider-Man Theme
Most of these are before my time, but I like ‘em anyway…
Secret Agent Man
The Monkeys
The Munsters
Andy Griffith
Batman
Daniel Boone
Rawhide
Happy Trails
Hawaii Five-O
Mission Impossible
Hawii 5-0 kicked major but, but let’s not forget
Route 66
Peter Gunn
The NBC Nightly News theme composed by John Williams used back in the mid-80s. I used to play it to calm my duaghter.
I’d throw in the theme from the old CBS Reports, but since it was “Appalachian Spring” we’ll just have to say “adapted from another medium”
I agree with a lot of these (Especially Dr Who. Anyone ever hear the remix by The Timelords?).
Also, Batman Beyond has a cool theme. The opening graphics fit the music very well.
Another vote for “The Jeffersons” theme song. I love that song!
Battlestar: Galactica
Loved that show. The theme is still is a thrill to listen to. 
SWAT
Wonderful instrumental number. Tres cool. 
Peter Gunn
Route 66
What can I say about these that others haven’t said better?
Space
This was a PBS documentary series on Space Exploration. It had a grand sound to it. Very nifty.
Hey. All of these are instrumentals.
Hmmm.
Sorry. Route 66 wasn’t instrumentals only. :o
Rawhide
Hogan’s Heroes (12 and under)
Batman (if you’re under 9)
Hawaii Five-O
Jonny Quest
HELL YEAH!
The moment I read the subject line, that was the answer which popped into my mind.
Nothing else comes close. Okay, maybe the theme from The Muppet Show, but… 
Inspector Gadget
Completists could insist that this ranking should include The Flash, Family Dog, Dilbert, the animated Beetlejuice, and Sledge Hammer. And I wouldn’t argue with them. Indeed, I would remind them to put Fast Times (the TV version of the Ridgemont High movie) on the list. But now we’re not even talking overall quality, just obsession.
Elfman, Mancini, and Mike Post. TV themes in a nutshell. No, people don’t rock-out enough to The Rockford Files. But they should.
“The Bill Cosby Show”, 1971 or so. Not to be confused with “The Cosby Show” of the 1980s. Great little Quincy Jones gem, and Bill himself warbles the nonsensical lyrics.
“HOO LORD! GONNA GET SOME RAGGETS…AN’ SOME ROLLS…AN’ SOME REEZINRIZINS, HA HA HA HA! EVERYDAY! LONG AS I’M AWAY…”
Here we go:
“Greeeeeeeeeeeeeeeeeeeennnnnnnnnnnnnnnnnn Acres is the place to beeeeeeeeeeeeeeeee, Farrrrrrrrrrrrrrrrrrrrm living is the life for meeeeeeeeeeeeeeeee!!!”
Cheers is pretty cool, too. I’m shocked that nobody’s mentioned the best T.V theme song ever - the theme to “All In the Family.” Jean Stapleton’s voice cracks me up every time I hear it.
Gotta add Magnum PI and the World News Polka.
*Politics and foreign wars. All the weather, all the scores.
That’s the World News Polka!
Business news from Tokyo. Stuff you saw on Koppel’s show
That’s the World News Polka!
It’s late at night, you’re wide awake and you’re not wearing pants.
So grab your World News Now mug and everybody dance!..*
" . . . I’m livin’ on the air in Cincinnati . . . "
Oh! The Monkees, how could I have forgotten? Yeah, and I like the “All in the Family” theme song too. Think I have it memorized by now.
Come on , belt it out with me!
GREEEEN Acres is the place to be.
Farm living is the life for me.
Land spreadin’ out so far and wide.
Keep Manhattan just give me that countryside
do do do do do
…
For pure singalong value I don’t think you can do much better than either Gilligan’s Island or The Brady Bunch.
The theme from Mannix is nothing but listening pleasure. Lalo Schifrin can incite me to aural orgasms.
Have I shared too much?
Malcolm In The Middle
King Of The Hill
MASH
Cheers
Absolutely Fabulous