That was one of my favourites too.
Dont have favourite but another one I liked was when you do the mission for DL and you have to get in the Blue Speaker van and try to persuade people to vote for DL instead o O'Donnovan, you have to shout abuse and its funny when Tony says 'O'Donnonvan is a Commy'
That was "Steering the Vote". Also, here are some other insults Toni says:
O'Donovan is a chunky.
O'Donovan has three wives.
O'Donovan hates America.
Who ate all the humble pie? O'Donovan.
i believe tony says: O'Donovan is a JUNKY not a chunky...