The lineup: (clockwise from top left) That guy, that other guy, that chick, and that guy.
Fart Factor: A perfect 10 out of 10. Guy 1 shoots it out with the grace of a swan. Guy 2 is enraptured by the thrill of release. The chick barrels forward with the power of her thighs, and the last guy makes it squeak so loud it whistles.