Well, if we're talking about unobvious combinaions... HP Sauce (or nearest available equivalent) on ice cream isn't bad, although I can't recommend it as a desert. And for the truly stupid, a sandwich:
Bread
Peanut butter
Cold sausages
Bread
honey
Marmite
Bread
Peanut butter
Ketchup
Bread
This is a good sandwich and I recommend it to anyone who can cut bread thinner than me, maybe you'll be able to fit the whole thing in yer gob before the sausages fall out.