Benelli with out a doubt, I've owned them all, the inertia system is trouble free, it is not gas driven and requires very little maintenance unlike the gas systems
The Browning A-500 listed above Used $850-1200, Remington 1100 Used $400-600, Benelli $400-1500, Stoeger new $500.00. used pricing all depends on model and condition. gunbroker.com is a good referance.
We have two Stoegers in stock. Nice wood. We have them for $449 each. They have the Benelli inertia system. Great gun. Only problem is they wont chamber the 3.5's. For that, you really need to look at the Benelli's. We have two in stock. They are in the $1400-$1600 price range. If you can live without the 3.5" shells, Stoegers are a great option. We also have some used semi-autos as well. If you live near here, let us see if we can win your business.
I am assuming you mean Semi-auto? If not, I gotta get me and automatic shotgun.
Everyone I talk to swears by the Beretta xtrema 2, and that is what they have at their duck camps. I have never shot one. I have spent some time with a Benelli semi-auto (can't remember model) and thought it was a great gun.
I've been duck hunting for over 30 years and I've shot most everything. Last year I decided to invest in the best shotgun out there. I didn't exactly know what that was, so I set out to do research and shoot a few before I decided.
Long story short, I went with the Winchester Super X3. Not a 3.5" but that wasn't what I was looking for (I shoot a BPS 10 gauge for geese).
Very light, little recoil, and swings very easy for me. Mounted a Pattermaster ER choke and spent hours patterning to come to the conclusion that it loves #1 steel.
Shoot one before you invest is probably the best advise here. I shoot a Beretta Xtrema2 with OUT the KickOff (KO) pad. You really do not need it. The Benelli is a great gun as well and as mike stated it does use the inertia system instead of gas which makes it recoil harder than any of the gas options. I have been hearing really good things about the Winchester SX3 but I do not have any personal experience with them. The Browning Gold Hunter was one of the more popular choices a few years back. My dad shoots one and has had several years (atleast 7 probably 10+) of trouble free operation. The down side is that they are heavy. Look into the Remingtion 11-87 as well. Again I have no experience.
So the short list. Beretta Xtrema2, Benelli, Winchester SX3, Remingtion 11-87, Browning
Beretta or Benelli. I had the privilege of going on a duck/dove/quail hunt in mexico a while back. Their entire stable of guns were Beretta 39x series guns that see some serious use. They said they use them because they are the most reliable guns around. I personally shoot a 390 and have never had a jam.
I will shoot nothing but Benelli's in the field. I have owned the old models and a couple of brand new ones. They take little maintenence and are solid dependable guns.
They are pricey. I happen to know a guy who has an M2 with only 100 rounds through it for $900. If you are interested PM Me.