There are so many great lines in this film.

"What else have we got?"
"Nothing"
"Liar. What's in your toolbox?"
"Nothing"
"Liar. You've got antifreeze"
"You bloody fool, don't you know you should never mix your drinks?"
"Bwaa ha haaa *puke*" - after drinking lighter fluid for lack of booze in the house and trying to find more

"You don't understand, there's something growing in there. Something alive"
"What, a rat?"
"It's possible. It's possible" - when referring to their sink piled high with dishes and crap

"Right you fucker, I'm going to do washing up. Stand aside"

"We've gone on holiday by mistake."