Not original but the one I use often is "sit down and plug your chair in"
or, "let's have a whip round and buy this guy a life"
or, "are you on your own?" !yes "I'm not surprised"
or, "no don't boo him, I have a soft spot for this chap...it's called a Swamp"
or, "does the nurse know you're here?"
or "ah, I was wondering who the club idiot was1"
or, I had just got up to sing one night and said I'd like to sing you an Irish song, guy shouts "go on Paddy sing an Oirish one" So I said "right this one's for the racist Bastard at the back" got the biggest cheer ever ;)
And Finally this from the old music hall comic Max Wall, he'd been through a rough time with the press over some scandal, guy starts heckling, Max waks slowly over puts his nose up to the huy's head and said "sit down sonny, I've been heckled by experts"