Oh, man, I forgot about Super Chicken. I stand by my list, but Super Chicken deserves honorable mention. My screensaver at work once said “You knew the job was dangerous when you took it.” Only one person got it.
I’ll go along with this as best cartoon theme music!
By the way, only the first verse of the theme was ever played on WKRP. The entire song runs for nearly three minutes and can be heard here:
Complete recording of WKRP in Cincinnati theme by Steve Carlisle.
I like this one better.
Too intellectual. Too many words. 
Perhaps in the tradition of Bill Murray’s bit, cable channel Nickelodeon used to have some hilarious fake-lyrics-to-themes commercials, to promote various of their Nick at Night shows. This was apparently twenty years ago (per the article I’m linking)–I haven’t watched the channel for a long time, so don’t know if they still show them. But engraved on my brain is this classic by the channel’s Tom Hill:
I have been known to sing it in the shower. :o Inquirer.com archives
I’ve posted it here before in the music appreciation society thread, but my favorite TV theme song is TWX in 12 Bars, the theme for Wall Street Week. Warning: Sexy but SFW picks of Louis Rukeyser in the vid. Control yourself.
It’s instrumental, comes in all important and big, marching along about the economy. Then there’s a soft, gentle electric piano/flute break, then the economy comes back to close it. It’s perfect, that’s pretty much how Rukeyser ran his show. It was hard facts about the economy, then the human side of it, and what it might mean. I listen to that 48 seconds pretty often. It’s a little masterpiece.
ETA: Good lord, Czarcasm, give us some warning next time. I can’t un-hear anything.
The Lonely Planet theme song is gorgeous.
I will second Gravity Falls and Cowboy Bebop and also add …
Buffy The Vampire Slayer
Johnny Quest is kick ass. There should be a thread just on great cartoon songs. I have so many favorites-- not all theme songs.
Unfortunately, I suspect the significance of this song was somewhat lost on the US audience. 
The Bugs Bunny Show
My all-time favorite! :cool:Funny you should mention it. This was on MSN.com this morning:
The Waltons
Monday Night Football (original)
ABC’s Wide World of Sports
Come on now, the rule is 3 greatest themes ever per post…
Love American Style
Star Trek
MAS*H
*The **THRILL **of **VICTORY **… and the **AGONY *of DEFEAT!
Ouch!
Nobody’s mention The Big Bang Theory
I once saw the “lyrics” to the Star Trek theme in some local rag back in Minneapolis in the '80s (probably The Twin Cities Reader). All I remember is
Space guys
in a starship,
oh-oh-OHHHHHHH-oh-oh-oh-oh-oooooooh!
Kiirk, and Spock, and McCoy-oy.
And Scotty, Sulu, Chekov, and Uhura, toooooo…