Caesar Guerini 20 and 28 gauge, Citori 12 gauge.
The 28 is all I shoot anymore for targets and upland. Waterfowl I use an auto 12.
I think the only reason I keep the 12 gauge o/u is because I'm adverse to getting rid of guns and it's nice to have a loaner.
I absolutely love my Browning Citori 20ga with 3" shells for pheasants. It's got the shorter 26" barrel, so it's quick to draw and the balance is perfect. I could not be happier with it.
I shoot a 12 ga. Winchester 101 with Browning extended chokes. SK/IC for sporting clays & quail, IC/LM for first season dove, LM/M for late season dove/pigeon, M/IM for waterfowl, F/Turkey for Turkey.
My daughter just got her first O/U. A 20 ga. CZ Redhead Premier. I ordered Briley chokes in SK/IC/LM/M for her. She shot her first dove season with me, and slayed them. I used it often this dove season too with the IC/M chokes. I think I got better percentages with this gun over my 12 ga.!
I don't have anything larger than 20ga. Depending on the use, I usually choose between my Browning Superposed 20g MOD/IC, Winchester 101 .410 Skeet, Win 21 SxS or bunch of pump actions.
I have had multiple Brownings and Italian double guns, but my favorite upland gun is my 20 ga. Cynergy with 30" tubes. I find a bit longer barrel helps my swing. That gun flat out puts down the birds.
If it works for you, by all means stick with it. Years ago Win. made a few of the 101 20-gauges with 30" bbls, and I have one. Wonderful upland shotguns.
Shoot a Browning Cynergy in 12 gauge improved under light modified for most upland applications. Favorite is a Beretta silver pigeon in 28 gauge. I have a Beretta in 12 as well as a Weatherby in 12 all shoot well. Have a friend who has shot 101's for years and swears by them.
I shoot Brownings and Berettas but my 101s hold a place in my heart. They were the gun I began shooting in high school (a loaner, no I didn't come from money). Pattern them and stay with what they like. I shot with a professional shooter who had the recipe taped to his stock (and with a 98% pattern it was an education to lose to him)