My favourite's when they shout the most inappropriate things. There was that scotch chap who shouted 'Fúck off, bignose!' at a man with a big nose, 'Fat ****!' at a fat lady, 'BOMB!' at a busy tourist site and 'BECAUSE HE'S A GAY MAN!' while his fellow touretter was explaining why he didn't have a girlfriend. Most amusing. Almost píssed myself, in fact.
I always watch Tourette's programmes when he's on. He should have his own show.