My favorites to sing along to:
Gidget
Timon and Pumbaa
The Muppet Show
Speaking of TV themes that awakened something, the notion of girls skinny dipping in a water tower seemed deliciously naughty to me as a kid (been keeping half an eye on this thread, and I don’t think this has been posted yet):
“A wiener hot dog makes her lose control!” 
Ja, sure!
@terentii Thanks for posting The Farmer’s Daughter themes (hadn’t heard these before, except perhaps when I was too young to have remembered them). I just added the second (jazzy) version to my phone’s Space Age Pop playlist.
Glad to be of service! 
I like to think of Congressman Morely on TFD as an ancestor of Commodore Matt Decker.
Surprised no one has posted any of these yet (at least, I don’t think so):
The theme in this clip (The Rebel) starts at 1:44.
OMG, that last one was exciting! Phew! 
Crap! I had this one paired with Branded, but it got erased somehow. Oh, well…
… And there used to be a little box of Tide in the lower left-hand corner!
Here’s an alternate theme for The Saint, just for good measure:
some from my childhood
Quite why there is a horsey theme running through these I just don’t know.
Here’s Return Of The Saint. The 70s loved their jazzy drums.
Words of Windom. 
Fun fact about the “George of the Jungle” theme: George was supposed to live with identical twins: Bella and Ursula. The twins concept was dropped but the theme song was never rewritten!
I don’t know where you got that info from. The lyrics are:
“Then away he’ll schlep
on his elephant Shep
While Fella and Ursula
Stay in step”
It was a little in-joke because he would call her “Fella” constantly.
Czarcasm, you are right! I stand corrected. Link to lyrics.
Funny looking fella who never shave.
I never realized how infectious this theme is until my daughter and I were laughing at an episode of the show on PBS last Sunday. I was able to sing it without missing a beat, despite not having heard it in decades. (My daughter was greatly amused.)
The polyester industry must have been hit hard when the show was finally cancelled. 
Danger Mouse always amused the hell out of me.
I love this theme:
I LOVE 
Wallace & Gromit.
Metalocalypse’s theme song totally fucking rocks!
Doctor Who, 60s and early 70s version, tho the 80s closing is cool too
The Muppet Show
I actually liked Star Trek: Enterprise
Golden Girls incidental music, not the theme. Gilligans Island incidental music was memorable as well
When i get to my real computer I’ll try to find links. Hard for me on a phone