I always found the best farm shotgun to be the one ones that went BANG every time I pulled the trigger.
Didn't matter if it was a single, double, pump, or semi-auto, as long as it went bang when I pulled the trigger, I was very, very happy.
Bayonet on a farm gun? What, after you shoot the ground hog with the shotgun (hopefully it went BANG!), you stick the ground hog with the bayonet and flip it over the fence line into the neighbor's field?
I guess along with going bang, my definition of the best farm gun is one that is SIMPLE. No fancy BOPOS (bolt-on pieces of shinola), no extended mag tubes, no holographic infrared ranging and vectoring sights, just simple, cheap, and to the point.
As far as I know, the HR Topper 20 gauge that I used to use while working on a friend's farm still sits in the corner of the barn by the work bench, with a box of shells on the bench, and is still used regularly to dispatch ground hogs, raccoons, and possums, the same as it has been doing since the middle to late 1970s.
BUT BUT BUT YOU DON'T HAVE A HYPERBOLIC FLEEM RENUBULATOR ON THAT SHOTGUN! YOU'RE SUCH A HICK!
It goes bang when I pull the trigger, what more do you want?
I'M SORRY, CAN YOU SAY THAT AGAIN, I WAS CHARGING UP THE RENUBULATOR.
Bang.
Oh well, if lots and lots of BOPOS makes you happy...