Italy's! I quite frequently hum that tune cos it cheers me up (although I prefer not to hear it on F1 podiums for the constructor unless it is the MIGHTY Minardi, but um... unlinkely we'll get a win)
Never heard the Iraqi one!
Least favourite -
God Save our gracious queen (stretch)
Long live our noble queen (yawn)
It has to be changed, if you can fit some words into the Thunderbirds theme tune then that would be awesome!