Give a choice, oddly, I don't care for auto shottys.
I see two ways to go: either a good pump shotty (Rem 870/Winchester 1200-1300-1400/Mossy 500-590) or a good side-by-side.
Granted, my thinking is heavily coloured through my historical use - limited hunting, typically home defense or military use.
Advantage to a pump? It likes abuse, it's easy to check to see if it's loaded, load variations aren't generally a problem, and more rounds in the magazine.
Disadvantages? Single firing mechanism, most are picky about shell overall length.
Advantage to a SxS? Easier to load than an O/U in a hurry, does NOT care about load length (as long as it's under the chamber max length, typically 3",) and you've usually got "two guns in one" if you get a double-trigger setup (left barrel breaks a hammer spring? Just use the right until you can get it fixed.)
Disadvantages? Only two rounds, and you have to know where the barrels are "registered" (should say in the literature, but usually ~40y.)
A side-by-side gives you more options for availability, but still stick with something fairly well-known. A good test before you plonk down your dosh for a SxS? Strip the barrels down to just that assembly (other metal parts okeh,) hang them in a loop of string with one hand, and "ring" them with a plastic or wooden screwdriver handle in the other. If the barrels are soldered tight, it will ring like a bell; if they're not, you'll just get a "thud" out of them. If they're not, don't buy it - one of the first things you'll have to do is get the barrels resoldered, which is not cheap! (And it's a pain to find a guy who can do it properly these days - the last one I knew that could do a good job of it retired 25 years ago, and died 18 years ago.)
But, a well-built SxS or pump will last you pretty much forever, with only minor parts replacements (mainly springs.)
"recon" (sic - reckon)(tm) "hihgly"(tm) "seceed"(tm)
"Outback AIDS - Alcohol-Induced Dizzy Spells"