Farscape - Season 2 Episode 9 -

The crew is attacked by a vessel, Zahn goes over to the ship to negotiate a peace. But the ship attacks again, the attack reacts unexpectedly interacts with the shields causing everyone on board Moya to switch identities, ie Aeryn is now Rygel, Rygel is now Crichton, etc. Now the crew must figure a way to get back to their original bodies.