I've had the best delts success (both definition and size) with lateral raises. I do 6 or 7 sets with 55-lb db's, and an additional few sets with 45-lb db's to the front, and to the rear at the same time; counterbalancing. I have a nice division between front & rear delts, and very decent size for my overall weight. I've never been able to go full-out on military presses... bad back.
Charles