Get a used gun - better yet, go to a large dealer with a trap or skeet range where you can shoot their used guns before you buy! It probably won't be the last one you buy so get one that you can get 90% or more of your money out of quickly as you develop your shooting and understanding of what works best for you.
In order, no matter how much I like the shotgun, it must fit. Then, it must fit. Last, it must fit. Basically, the gun must shoot where you look. See bottom for a simple method for determining that. Thankfully, I'm 5' 10" and 180 lbs. I fit most shotguns.
I have shot over 85,000 targets - nearly half of those were sporting targets. Not bragging, just establishing.
In the beginning, I shot O/U guns exclusively. Had a 32" Browning European spec, 325 and shot it for all games except trap. Weighed 7.5 pounds and was deadly for sporting and skeet. I shoot low-gun skeet for sporting clays & mounting practice; don't let anyone tell you a well balanced 32" gun won't do at skeet. I could walk up more than half way from station 8 to the low or high house and break targets from a low gun position. I shot a 29" O/U for trap; it was stocked a bit higher (Winchester 101 American Flyer edition). That was 1991 to 1993. Won a state skeet championship with the Browning and several "meat" sporting shoots. The 101 netted me a top spot at the '93 NCAA nationals in trap too.
1993 to 1999 - Army service across about 10 countries...
1999 to 2001 -Active duty done and our family grew. I became a civilian again.
2002 to 2010 - The 32" 325 was still a go-to gun, but the Euro vs. dollar future allowed me to trade up to a Perazzi (2002). It was a 29.5" (1.71kg barrels, if you follow those type of things) slightly heavy by the current trends and it was about 8.75 pounds total, model MX2000/8, removable leaf spring trigger, selectable. The trigger was so good that I found my shooting & timing needed to adjust to it. I did some wonderful shooting with it, trap, trap doubles, trap 27 yard, skeet, sporting, money games. Had the "small bore" barrels @ .725" too. It was factory stock except I had the insanely abrupt Perazzi factory forcing cones opened from about 1/4" long to about an inch. Due to soaring Perazzi prices and lack of recent trigger time, I was able to sell it due to lack of use earlier this year. Perazzi guns have a tendancy to crack the butt stock right behing the rear tang. Mine did about a year after I had it. Nothing came apart; I spread the crack, put in a bit of gorilla glue and clamped overnight. Since the crack was barely visible on the outside, it was perfect again after the glue job. If buying a used perazzi, take the buttstock off and look inside where the lower tank mates with the stock - many will show signs of repair and most will never crack again, mine didn't. I think you could shoot a million rounds through these and MAYBE need a slight rebuild. Rock solid.
2011 - Purchased a serious gas gun. Beretta 391 12 ga. Teknys sporting, 30". Checked it for point of impact and adjusted the stock accordingly. Won the first sporting shoot with it - 453/500, or just over 90%. It's only fault was remedied when I replaced the shell carrier with a Beretta 390 version - actually work was done by Cole Gun. This gun is magic! It patterns exactly where I look and recoil seems like 1/2 of what the Perazzi was and it's a pound lighter! It has proven to be extremely reliable. I keep the bore clean and clean the rest about every 500 to 1000 shots. It is also a skeet hammer. I think this Teknys is the best target buster I've ever used. It's so good that I really don't miss the Perazzi. It didn't take long to get used to the blue nail polish inserts as targets are turned to dust. I personally know one very highly ranked (world rankings) sporting shooter who loves Beretta autos; he shot a 390 for a long time and did it with just 2 chokes; improved modified and threads. Contrary to what many will have you believe, shooting a couple shots of lead target loads, with todays plastic wads, through your choke tube bare threads will not harm a thing. I do not recommend it though. I think it was a play on rules for FITASC (international sporting basically) - where you must shoot with the single choke that you start with. I think the rules have been tightened up since then.
Other guns I've used enough to share opinions;
Beretta 680 series: Great guns, rebuildable and very reliable. Buy used, many out there. Don't scrimp on barrel length. I currently have a Silver Pigeon II 20/28 2-barrel set with custom wood, 30". It is a wonderful hunting gun and lots of fun to shoot social skeet or sporting with. It is heavier with the 28 bore tubes vs. the 20 bore; 6.5 pounds with the 20 ga. barrels in place and a few ounces toward 7 pounds with the 28s. I don't like Beretta's barrel selector. Seems it likes to move on its own, so when Cole upgraded the wood I had them install a tiny set screw in the tang safety that locks the selector portion of it in bottom barrel first position. No more issues. Now, it is near perfect and pretty too.
Beretta 303 series: I had a 32" trap for a bit early in 1992. The gun worked flawlessly and its internals were finely made - much more so than the Remington 1100s of the day. I sold it quickly because I found out I couldn't shoot it worth a darn - it didn't really fit me. I got my son (12) an old Beretta 302 in 20 ga., 28" barrel. It is a 3" field gun, but handles standard target 2 3/4" shells just fine - of course that was after it was cleaned very well. He loves it and shoots it very well. Buying one of these on the used market will not be a bad choice.
Remington 1100 / 1187 series: Good guns, buy used. Keep a handful of O-rings and some CLP with you. These guns can keep up with the best. Maybe some trigger tuning and frequent cleanings are their only detractors.
Winchester Model 12: I've had several because I like them and the factory trap-model stocks fit me pretty well. There are many out there that have been down many miles of road; they still work but are fairly well used. Current inventory includes a pre-64, non-monte carlo, pigeon grade trap with factory modified choke. The gun appears to only have seen a couple trips to the range - it is really minty. I use it occasionally for trap and for the occasional pump gun only sporting shoots held for fun in parts of the midwest. It is a wonderful 16 yard trap singles gun.
Benelli: I have a "Legacy" model from 1997, 12 ga. 28" barrel. It was purchased to be the feed it anything gun - steel, tungsten, etc. This model is 3" chamber - not 3.5" like many Benellis you read about. Mine handles 1-ounce light target loads very well. I think this semi-auto is the most reliable out there. It has NEVER failed to cycle - even after a 2500+ personal torture test, it was running just fine. I broke down and cleaned it out of pure guilt, but I'm sure it would have kept on going for a long time without attention. It has been frozen shut in a duck blind and worked just the same. One of today's real advancements. Only thing I don't like about it is the pistol grip area - reach to the trigger is quite long compared to all my other guns. It will beat you up a bit because of its recoil operation and lighter weight. I can't think of a better late season pheasant gun. I presume the newer Benellis function just the same, but it appears they have done some funky stock design stuff to help mitigate the recoil for competitors. My gun has figured walnut because I like that. I've even shot this gun at live pigeon events - it's that reliable. Got some funny looks until I was leaving with a wad of cash - it worked.
Kreighoff: Good guns, find a used one, rebuildable and very consistent. Trigger quality on par with or better than Perazzi, but more complicated action works. Typically are not balanced well to my tastes, but that can be adjusted as well with barrel length, backboring (the only real benefit of which is removing weight from barrels).
Winchester 101 series: I shot one for trap a couple years as noted above the American Flyer version. Did real well and liked the gun. Only once it let me down; cracked at the pistol grip area. Hairline crack and was repaired under warranty. No issues after that - was a smoker trap gun.
Browning, Belgium superposed: I've had several and like the Winchester model 12, many have been down the road a while. With some life left in them, they are wonderful. I like the straight comb "trap" models without the silly broadway rib. Had a 1963 "lightning" trap, 30" M/F choked that was a deadly doubles trap gun. It worked well for sporting too. The standard trap (non-lightning) models from the 1950s, 30" barrels are hard to beat for a general purpose gun - this was before the "broadway" trap bowling alley style rib became popular (man - I don't like those). There is a minty 1955 or 1953 trap model at Fugate Firearms right now for a fair price. Very rare to see a superposed trap for sale that is essentially new - I might just have to buy it! The chokes are usually tight and tighter on these and the berrel walls are often thinned at the muzzle from factory regulating - this means that even thin-wall screw in choke installation often won't work. If you like these, just open the super tight chokes to about modified or whatever and have fun.
I've shot some very high-dollar guns, friend's guns mostly, and some my own. I remember shooting one seriously expensive and highly regarded custom trap gun one day ($35,000+ probably in 1993) and I couldn't hit with it and it ended my day because the fit was so poor for me that the recoil caused me to shut down.
For fitting a shotgun, try this simple method. Get a big blank piece of paper or cardboard and place 16 yards from you. Put an aiming dot on it about 1" in size. Grab a half dozen shells and carefully, but naturally shoot at the dot until the target develops a hole (usually just a few shots) - this is your center of impact. Mearsure from your center of impact up/down, left/right to the aiming dot and move the comb of your buttstock 1/16" for every inch you want the impact to move. Adjust your stock (Beretta and Benelli autos make this real easy with shims), or have a good stock maker adjust your inletting to accommodate, or have your stock "bent" by a professional. Retest after the adjustment - should be perfect.
Oh - and I never pattern my shotguns at distance. I only point of impact test as described above.
regards - redleg