A SuperFreakonomics Contest: Underappreciated Complements?

Iced tea and lemonade are hardly perfect complements — they can each be happily consumed individually — but more and more I see them being served together. I have always known this combo as an “Arnold Palmer”; increasingly, however, as in this ad at the New York chain drugstore Duane Reade, it is known simply as “half-iced tea, half-lemonade.”
I like an Arnold Palmer just fine, but to my taste the best combo drink of all time is a cranberry juice and Fresca. What? You’ve never tried it?! Thank me later.
This has gotten me thinking about other wonderful complements in life. Surely many of them are in the realm of food and drink. But there’s also driving a convertible in cold weather with the heat on, e.g.
What are some of your favorite — especially underappreciated — complements? Tell us in the comments section and we’ll take five of the best and vote for the favorite. Winner gets a free copy of new SuperFreakonomics paperback.