What Live CDs Do You Carry Around?

TPC asks: "I recently acquired a small CD case that fits 12 CDs. I figured that it would be useful to always carry around a few CDs to use when helping others with computer issues, or in case something goes wrong with my own computer. However, I'm having a hard time deciding what CDs to pick, and there are probably many hidden gems out there. I'm sure I'm not the first person with this idea, so I ask you: What 12 live (and otherwise) CDs would you carry around?"