I am in the market for a shotgun. Due to medical reasons I can't use a 12ga. because it is too much recoil, believe me I would if I could but I can't. So I am thinking instead of going with a 20ga. I fired a pump action 20ga. mossberg and it was right on the edge of my recoil tolerance, this was while hunting so it had a magnum load. I was thinking that if I got a gas operated-semi and real good recoil pad I could handle a 20ga. for a day of hunting, or informal plinking, what have you.
I would like to be able to use the shotgun for as much as possible, hunting, skeet, trap, and maybe even home defense (I would get an 18 inch barrel for this). So I would also like it to be reliable.
Right now I am considering an 1100, 1187, or Benelli however I have heard that Benelli's are recoil operated and kick worse than the gas operated ones.
Please tell me what you think.
Thanks for the help.

Beretta 390 is about the lightest recoil 20ga. Unforfunately they are no longer in production. A close second is the 391. Good Luck.

A  non- lightweight Rem.1100 would be a good choice.
Franchi's are hard to find but they are nice as well.

+1 on the Beretta A390.  I have one in 12ga. and the recoil with low brass field loads is noticeably lower than the same brand & load from my 20ga. Mossberg 500.  

Thanks guys for all the information. I went to look around and see what was available. I thought I would start at Walmart and look for an 1100, instead they had a 390 in 20ga. with a 26 inch barrel for $450. I could not resist. I had a rather unpleasent buying experience at Walmart but to me the price made up for it. I am suprised that they still had one, it was not even listed in their books it must have been there a while.
I took it to the range and it was a blast hoot.Thanks for all the help.

you had an unpleasant experience at walmart.  Nooo waaaaayy.  I'm just teasing.  Thanks for bringing this subject up.  I'm interested in it.  I've got a 12 gauge and some of the parts of our state require pistol, shotgun, or muzzleloader for deer.  The 12 gauge slug is real fun to shoot.  especially from a bench.  I got the brenneke managed recoil and they we're a joy.  I shot them kneeling though instead of a bench.  Accurate too.  I printed a 3 round shot of 3-1/2" at 50 yards.  Like I said, kneeling.  Mines a smoothbore so I know I could get better with a rifled barrel.  At least I think.