Loot: 
Lather. Rinse. Repeat.
We think the Jargon File defines recursion best:
recursion: n.
See recursion.
"In order to understand recursion, one must first understand recursion," printed in white on a 100% cotton, dark chocolate t-shirt.
Note: The earliest version of this shirt had a period at the end before we thought better of it. So if you get one with a period, cherish it. It's a limited edition.
