Not to be predictable or anything, but in the UK, I think it's generally accepted to be this spooky bugger:
https://www.youtube.com/watch?v=6J_3rsEwYVEThat haunting piece, in its various forms, has sent children scuttling behind the sofa for a good fifty years now, and it's
still one of the best on TV, and certainly the most recognisable tune on British screens. That's a roaring success through and through.
I've got a really odd favourite theme song, though. It's only ever used in the first episode of each series of its programme, and it's way less iconic than the show's regular theme (which is
incredibly well known), but to me, it's one of the most exciting tracks in the world.
https://www.youtube.com/watch?v=r7BBV2y0ipQWasn't even composed for the show. It's a piece called "The Fury of Schmidt," by Rolfe Kent - no, me neither. Originally from a film called About Schmidt, but it's an absolute masterstroke in song selection. Sets the tone perfectly - classy enough (and
much classier than its US counterpart), but there's a little bit of pomp, and just as much mischief. Definite favourite.