The best autoloader?????
The question is like a complex mathematical equation that includes variables like "brand loyalty", "prejudice", "personal preference", "aesthetics", "taste", "value for money", "past experience" etc etc.
All these parameters vary among us.
My own personal opinion based on my calibration of requirements are as follows.
Remington 1100/11-87: Good looks but old design (technology), too much maintenance required (O-rings etc.). This is the one I would give the least consideration (sorry, Remington fans).
Baikal MP-153/Remington SPR-453: The best autoloader for the field (waterfowling). Tough, durable, reliable. I have a couple of them and their gas-operated mechanism function flawlessly in any kind of condition and despite all the abuse I subject them to. They are the AKs of shotguns. The engineering is great but the finish is very basic. A bit on the heavy side but very little recoil (even with 3 1/2 inch). Best value for the money.
Beretta AL-391/Etrema etc.: The shape I don't like, but this gun fits me extremely well. Finish is good and the design/engineering is modern and most owners I know are satisfied. Gas operated action is a plus for heavy loads. Great choice if you don't mind spending the money.
Benelli SBE/M1 etc.: Modern designs that are easy to clean and maintain. High reputation and pleasant styling with nice finish. Only drawbacks are high price and a bit too much recoil with heavier loads (inertia action).
Browning Gold/Winchester SX2-3 etc: Good guns that are pleasing to the eye. I find them comparable to the Berettas. They don't fit me as well as the Beretta but I am more attracted to these. A slightly more competitive price makes them even more attractive.
Franchi Raptor/Predator etc.: I don't have experience with them. They are probably good guns at reasonable price. I find their shape a bit weird.
I would not consider the Turkish made autoloaders such as Escort or H&R. They are the cheapest offerings on the market...and they are cheaply made. Not a good investment as they don't last very long. Stoeger 2000 as a bit better (and more expensive) but still not up to the level of the firearms I described above.
If the question was: What is the most interesting autoloader?
My answer would be:
The MTs-28
http://www.kbptula.ru/eng/sphu/hunt/mts28.htm
Combo autoloader:
20 gauge and 22cal (over under) both barrels semi-auto loaded.
Very few hand-made on special orders. Please don't ask abou the price.