well it depends on your budget and your preference !
Beretta Makes a nice shotgun But so does Remington and browning ,(IMO) (Beretta's customer service sucks )
In skeet and sporting clays, the advantage of an O/U is that you can have a company like Kolar or Briley and 3 sets of tube inserts so you can use the same gun to enter into all events. There are 12 gauge, 20 gauge, 28 gauge and .410 events. My set of custom fit Kolar tubes cost $1800. My choice of O/U was about $4000, plus A $450 Americase to carry it all. If I didn't have a tube set, I would need $16,000 for shotguns and another $1900 for four Americase gun cases, plus carry all that weight around and have to pay at least $200 extra on every flight to bring all four guns with me. I couldn't bankroll that.
If you want to go with a semi auto check out a Benelli Super Sport. My first sporting clays gun was a Berretta 390 that I bought new, I couldn't make it through a full course with out it jamming toward the end. I put more then enough rounds through it to break it in and was meticoulous in cleaning and lubing it but it would start jamming the last couple of stations. This was with new high quality ammo also. I sold it and bought a Ruger red label O/U, had it throated and ported by magna port and it shot great but I sold it shortly after I bought my SS. Most people that I know that are really into sporting clays shoot O/U's but I prefer a semi auto.