Get ready for a very long list. I have quite a bunch. Most of these are ones that aren't out there at all, or are just plain rare:
-Wordplay: I don't know about you folks, but I love this theme.
-Boardwalk and Baseball's Superbowl of Sports Trivia: Same reason as above.
-Supermarket Sweep: Pretty much one of the best themes of the 90's.
-Shopping Spree: Another great 90's theme.
-Jeopardy! '78: The closing music was just awesome.
-Whew!: Somehow, I can't believe this wasn't mentioned yet.
-Make the Grade: This one's a personal favorite of mine. One of Edd Kalehoff's best Nick themes [excluding DD, of course].
-He Said She Said: This one applies to the theme later used as the "Who's Who?" cue from WML?.
-It's Anybody's Guess: With the amount of Stan Worth's work that's turned up since the SS theme was released on CD, I'm surprised this one isn't anywhere. A little repetitive, but still good.
-Eubanks Dream House: Of course, the 6-note sting heard in the bonus round has become quite famous in the game show circles, but the main theme is pretty darn cool.
-Break the Bank '76: If a higher-quality version of this turns up, I will be so happy.
-Split Second '87: Too bad all we have of this one is that chopped-up-sounding one.
EDIT---Body Language: This one wasn't too bad either.
Honorable mention: Bumper Stumpers, Hit Man, Hot Streak, Headline Chasers, Big Showdown, Starcade, Trump Card, Make Me Laugh '79