Rifled barrels are best with Breneke (saboted, hour glass shape) slugs. A smooth bore won't stabilize 'em. The Breneke slug's exterior ballistics, as well as accuracy out of a rifled barrel, is a significant improvement over Foster type slugs. Hunters who hunt deer with shotguns (some states like Indiana mandate shotgun or black powder) prefer the accuracy and extended range effectiveness of the Breneke slug/rifled barrel combination.
As far as home defense, it don't matter. I'd rather not have a rifle sight on a shotgun in defensive shooting with buck shot. I can get on a target instantly with traditional bead. I don't need no stinkin' sights on a shotgun.
I don't "aim" a shotgun, I point it, just like shooting birds only the target is much bigger and it ain't moving and dodgin' and if it is, I can hit it anyway with a shotgun. Besides, it's what I'm used to in a scatter gun. I've been hunting forty years with a shotgun and never had a set of rifle sights or a scope on one. For deer hunting, I pick one of my rifles. I don't live in Indiana.
If I did live there, I'd use black powder, anyway.
A rifle sighted shotgun could be useful for turkey hunting, bear defense, and such. There are uses for 'em. I've been turkey hunting once and collected a tom at 40 yards with my bead sighted side by side using the full choke barrel. Didn't need rifle sights, but they would be advantageous in precisely centering the pattern on a tom's head, I'd think. I could see that. But, for home defense, I don't need no rifle sights. I keep the old side-by-side in the bedroom unloaded. It's right by the bed. I was keeping it out in my shop, but I was worried about the environment out there, so I'll take it out there sometimes, but rather keep it in the AC to prevent corrosion. I've had that thing since 1971 and it still shoots just as well as it did 35 years ago when I bought it. I've killed ducks, geese, doves, quail, rabbits, squirrels, turkey and DEER with it. Mostly was a duck/goose gun with occasion doves. Now, it gets little use, but it's still a good ol' gun. In a low light situation, I am so familiar with that old thing I can just point it where rifle sights would just obscure the view. Probably couldn't pick up a sight picture with it anyway if it was too dark.
As for the best "all around barrel", I'd figure that'd entail at the very least an