Dude +

[Charlie Bigtime]

I'd swap my belly button for a foo foo any day.

 

[Groucho]

I'd have a hand attached to my chin so I could smoke, hold a pint, and text people all at the same time

I'd like to grow a ZZ Top-length beard, tie it to my pubes and strum it like a harp.......

 

[Piijt]

I'd like an extra liver so I can fully enjoy destroying the one I have now

 

[sportbillyblue]

an extra leg ... gap in the market apparently