Your level of hilarity will probably depend on if you're British or not, since most of the expressions I find amusing are British. If you are British (or Irish! -- for Niamh, Brigid, Barbara, Ann, Ellen and any other lovely Irish people I've forgot), please feel free to chime in with your own!
Argy-bargy: A lively discussion.
Ding-dong:Similar to the above, but more aggressive. As in: David Cameron had a right old ding-dong with Her Majesty (not really, but it's kind of funny to picture).
Got the hump: If you get the hump with someone, you're annoyed with them.
Luvvly-jubbly: Means 'lovely'. I detest this one! If you've ever watched Jamie Oliver, you know this expression. It was made popular by the TV show Only Fools and Horses, which always seems to be on telly at any given moment in time.
Off your trolley: Bonkers! Incidentally, 'trolley' also means 'shopping cart'.
There you are! Some funny word combos to get you through to the weekend.
Any entertaining regional expressions in your part of the world?