i would have to say my favorite song on t.v would be the facts of life opening. Once you hear it man does it get stuck in your head.

My favorite song from a tv show would be remy zero's save me from smallville's opening or  kansas carry on my wayward son from supernatural's opening. 

Easily Song of Fire and Ice from Game of Thrones. Epic score and never gets old. At least once a week I will over hear someone whistling the theme to themselves. 

I kinda think The Big Bang Theory theme song is kinda catchy, as well as the one for Full House. Just talking about it gets stuck in my head.

The Bo-bobo theme song opening hooks me everytime, I can't help but sing along with it like a crazy person.

Mine has gotta be Snow Fairy from Fairy Tail. It's the main theme song, so I get to here it before every episode! :-)  FAIRY, WHERE ARE YOU GOING hikari zenbu atsumete kimi no as***a terasu yo OH YEAH kikoeten no kako no koe wa? OH YEAH karetatte sakebu kara OH YEAH kikoeru made kimi no kokoro ga OH YEAH OH YEAH tsuki to taiyou no haitacchi wasuremono wanai desuka? okashii na kimi ga inai to hoshii mono sae mitsukaranai SNOWING sunao ni egao ni nareta no wa futari yorisoi kasane atta "jikan" ga aru kara FAIRY, WHERE ARE YOU GOING hikari zenbu atsumete kimi no as***a terasu yo OH YEAH namiuchigawa ni ukabeta kanjou itsu no manika orenji sae shiroku kawatteku kisetsu OH YEAH bokura futari mitsumeteta RAINBOW ima wa omoide no naga de nanairo ga yuki ni kawaru fushigi dana kimi ga warau to boku wa sukoshi dake tsuyoku narerunda SNOWING konna ni hitori furueteru kimi no soba ni yorisoi tsutsumi komu koto mo dekizu ni FAIRY, SLOWLY BUT SURELY YOU'RE WALKING YOUR WAY, HANG IN THERE! warau koto sae wasureteta boku ni mahou wo kakete egao hitotsu de subete wo kaeta kimi wa boku wa no FAIRY SNOWING sunao ni egao ni nareta no wa futari yorisoi kasane atta "jikan" ga aru kara FAIRY, WHERE ARE YOU GOING hikari zenbu atsumete kimi wo terasu yo SNOWING sunao ni egao ni nareta no wa kimi dakara kimi to datta kara SNOWING FAIRY kimi ga kureta hikari zenbu atsume sakebu yo SNOW FAIRY DON'T SAY GOODBYE

You just took the initiative and posted the whole lyrics of the song huh. Lol

The opening theme from season 1 of Vampire Knight. It is the best. And I suppose season 2's theme isn't half bad either.

My favorite song from a TV show is the opening to Steins;Gate called Hacking to the Gate. Hacking to the Gate. I really enjoy it. I have other songs that I like better, but I do not believe that they have ever been placed into a TV show as of yet... 

For me, its the French Animated show Code Lyoko. The main theme(both the short and full version) in English AND French is just awesome and catchy. Furthermore, the show has an actual music album from which they played a couple titles within one episode, which you can watch here: Music Soothes the Savage Beast 10:45  and 20:10 mark respectively.