If you could start with one power up that you can use at any time (only once) what one would it be?

Basically if you could have 1 power up that you start with that you can use at any time in a game. But you can only use it once what power up would you want to have?

Here the list of power ups (from zombies) that you can  have

Insta kill

Double points

Max ammo

Nuke (kills all zombies on map you also get 400 points)

Carpenter (fixes all barricades)

Fire sale (random box shows up on every random box spot and the box costs only 10 points)  lasts 20 seconds

Death machine (use of the death machine chain gun)

I would want the fire sale so I can quickly and easily get some good weapons early on.  Thought the death machine is pretty fun to use...