Only one
Benelli SBE, left hand. Got one of the second generation camo lefties, it'll shoot anything I feed it from 2 3/4 trap loads to 3 1/2 tungsten without so much as a burp. Not the best trap or bird gun, but it'll kill any duck or goose I care to point it at, so long as I do my part. It'll tear down in the dark and reassemble without issue.
Granted, I own 6 shotguns, and while there is no perfect gun for all applications, if the requirement is "only one", that'd be my "go to".