For Valentine's Day, I changed a faucet.
The hot water side had been leaking for a while (I'd taken to going under the sink and opening and closing the supply valve as needed).
It went okay; the only big question was whether or not I needed to use plumber's putty.
Oh, and teflon tape: It's really hard to wrap around threads in a confined space. Also, it makes it easier to (almost) cross-thread the supply line.