Benelli Super Black Eagle for geese and ducks in the lower 48 and late season ducks up here. 3 1/2" Kent Tungsten Matrix #1's for geese (awesome) and bismuth 2 3/4" #4's and Federal hi vel #2's for ducks w/ IC choke. I like that the bismuth acts like lead in the choke for first close shots over decoys, then the following steel loads come out the same choke in a full pattern for the longer shots that come next.
Early in the season up here I use mostly a Ruger RL 20-gauge 26" over decoys, either steel or bismuth or in combo with appropriate chokes. Fast handling as a quail gun, and wicked as I need inside 40 yards, my normal shooting distance when there's still leaves on the alders and willows.
Used a ML double 12 for a long time before steel came along, and regret trading it off before loose bismuth came along. When I find the right one I'll pick it up and start doing that again. Way fun, and surprisingly effective with 1 1/8 of lead in the good ole days.