Although I have used others my 7lb Lefever 12ga FE with a set of Italian 26" bbls choked .012/.025 has served as my #1 go to gun for the past 43 years. I highly suspect if all the guns I own except one had to go, it'd stay. There's not much game that can be taken with a shotgun that it isn't capable of taking. Those exceptions require a very special purpose gun, not suitable for much variety. This would include both the little'uns & the extra big'uns.
One thing is for certain for a one only gun, I have no desire for anything but a double, unless we perhaps wanted to include a nicely balanced drilling. Personally I don't think when we start having it with 5 sets of bbls we are really meeting the criteria of the question.


Miller/TN
I Didn't Say Everything I Said, Yogi Berra