That really depends on the user. I've seen a wide variety of shotguns used. This year alone in hunt camp there were two 12 guage Rem 870's, a Winchester 101 over under 12 gauge, a Winchester side by side 20 guage, a Beretta and a Stouger semi auto 12 guage and a Browning semi auto 20 guage. And there were only 3 of us! Dove season is a great time to experiment with different guns and guages. Everyone has a different taste for their shotguns. Play around with several and find out what fits you best and works the best for you the range and and amount you are shooting.
i have a mossberg 835 12 ga, remington 1100 12 ga,browning a5 12 ga, a mossberg 500 12 ga, a springfield 67 12 ga, and i use all of them. so find a couple u like and don't mind getting torn up and have at it. also if you've got wood furniture you wanna keep nice spend the extra coin and get some synthetic furniture to use for hunting and have at it.