"Diaper Money" by The Lonely Island
If there's one thing I've learned from my friends who are parents, it's that diapers are expensive. I can't quite relate, as I am one of those freaks who has no children and lots of dogs, but I can imagine how costly it must be to replace a pair of polymer underpants every time a baby poops. I don't own a grave plot either -- yet -- but as an adult, I have thought a great deal about what will happen to my remains when I die, and whether or not my tombstone will have minimal typos.
The real meat of this song, however, is in the J. Orgus section about the status of marital intercourse with your wife. People say that Kanye and the Jigga man are real, but I don't think there's anything more real than singing about how your wife won't have sex with you because she hates your guts.
"Business Time" by Flight of the Conchords
How to sum up adulthood in one word? Routine. "Business Time" nails this perfectly. As a teenager, you think you will grow up and look awesome all the time and always have fresh breath, and you'll constantly be having spontaneous sex where you are wearing the perfect outfit for the occasion and there will be a bear rug under you and a roaring fire in the background.
What actually happens, however, is that you will realize that it's a Wednesday, you're not too tired from work, there's nothing good on TV, and you're ready to go to bed anyway. You'll also realize that you don't always have fresh breath, and brushing your teeth really is a very important part of foreplay. As for the sexy outfit you had planned? It's an old t-shirt from work. That's right, the one with the curry stains. You told yourself it would never happen to you, and it did, and Flight of the Conchords just told everyone about it.