This has without a doubt been the most difficult list I have ever compiled. TV has been such an important part of my life, to try to chose the best theme songs is like choosing your favorite child. But since I have no children...
Before I start, I should lay out my criteria as this topic is subject to many interpretations.
I) I had to like the show. No matter how good a song, if the show sucked (to me), the song would too by association. Thusly, goodbye Baretta. Despite the cockatoo and the ridiculously awesome lyrics "Don't go to bed with a price on your head... don't do it." I never liked the show so the theme is out.
II) Just hearing the first note had to make you want to drop everything and watch that show. In this sense, it's really "the best beginning to a show". Perhaps the best pure theme ever for a TV show is the Greatest American Hero, but if I hear it today, I don't pine for an episode of William Katt in his red tights and blonde afro, I just sing along like I did in 6th grade music class. Maybe this is a reflection of rule one, but the point is when you hear the song, your blood should get pumping to watch some televison.
III) It had to be cool in some way. Gilligan's Island, the Beverly Hillbillies, Brady Bunch, Love Boat, the Flintstones... all great, epic themes, but, in the end, just not cool enough.
10) WILD WILD WEST James Bond in the 1890s... the cartoon beginning with a cowboy taking a shot of whiskey, playing cards, shooting a man dead and kissing a woman then punching her was incredible. No better show to catch in the afternoon when you're supposed to be doing geometry homework.
9) HILL STREET BLUES Okay, maybe it's not cool, but this was a great show. And this was the first show that I remember being appointment television, sitting down with the whole family to watch. And it does set the tone for the show and proves the mastery of Mike Post.
8) BUCK ROGERS IN THE 25TH CENTURY 
I am a sucker for space shows, especially with babes like Erin Gray (okay, I'm biased as I did play lazer tag with her... true story). But the narration starts this theme off right... and who could forget Twiki and Dr. Theopolis? Okay, they sucked, but this was a good show and a great theme.
7) HARDCASTLE AND McCORMICK 
"DRIVE... push it to the floor while the engine screams... DRIVE... driving like the demon that drives your dreams." This song rocks which is why it in utterly inexplicable that they replaced it in season 2 (with a song by Joey Scarbury of GAH fame). In fact, this show was really boderline, but the song is so good it's on here. And the car was cool.
6) WONDER WOMAN 
All they had to do was show Lynda Carter in her bra and panties and they had me. But they did more. Much more. "In your satin tights, fighting for your rights, and the old red, white and blue." Genius. And patriotic.
5) THE INCREDIBLE HULK "Don't make me angry. You wouldn't like me when I'm angry."
4) MIAMI VICE No show was hotter in the late 80s and the music made the show starting with this Casiotronic theme. That and a Ferrari which proved to be a successful formula for a theme.
3) SUPERFRIENDS 
With Judge Smalls narrating, this theme represented all that was great with Saturday mornings (especially before Zan and Jayna). It is so much better than the regular Friends theme.
2) MONDAY NIGHT FOOTBALL This song has defined football for over 20 years. The sacrilege that has been perpetrated by Hank Williams should bow at the altar that is the real MNF theme. Listen to it and hear Howard Cosell talking you home...
1)THE SIX MILLION DOLLAR MAN Number one and it's not even close. I still get chills listening to this beginning. How many themes contribute so importantly to the lexicon of 6 year old boys (and me)? This theme absolutely defined the show and I defy anyone to listen to it and not want to watch Colonel Austin battle the Fembots (or Sasquatch). Six million dollars? I say it is worth every penny.
In fact, treat yourself to the video of SIX MILLION DOLLAR OPENING CREDITS
*And if they continue with their plan to make a Six Billion Dollar Man movie with Jim Carrey and give this tv show the "Starsky and Hutch" treatment, well... Jim Carrey will be dead to me. Don't mess with greatness.