Firefly. If I haven't watched it for a while, the second I hear that music, a huge lump rises in my throat. And I hate country, but those lyrics are too much.
Just watched the entire series and Serenity film via Netflix streaming.
Now one of my favorite series ever watched. I love the Buffy series
as well, but 14 episodes vs. 100+ (guess) makes Firefly stick more for me.
Firefly. Nothing else comes close, though BTVS is #2 high above the rest. I never really got the Angel theme, and I don't recall the Dollhouse theme at all. However, I could sing you the Firefly theme right ____ing now. I could "tweedle dee" some mouth guitar for the BTVS one too. Two very memorable themes there.