At this point I think the very best of the best would be tungsten BB or T's like the now discontinued Remington HD-BB load, Federal tungsten BB predator load, or the Dead Coyote T’s coupled with a choke of.050” - .060” constriction from your particular bore size. My pattern testing and in the field hunting experience would seem to indicate that this combination will give the max number of appropriately sized pellets (BB) which are harder and heavier than plated lead, fast enough at 1,300 fps for good energy and with considerably better pellet penetration on game. This type of load has patterned very consistently throughout all my shooting. A new shooter or an older one that wants to try something new would do well to begin with the Tungsten BB/T shot loads and a choke combination of .050” - .060” from their own bore size. This compares to the newest cutting edge magnum type rifle cartridge/bullet combo in the rifle hunting world. The downside? They are expensive!
For an inexpensive alternative I look back at the old standard No. Four Buck. Much less expensive than the new fangled hi-tech loads and effective enough for most shotgunning of called predators. IMHO, the No. Four Buck coupled with a good choke of the same .050" - .060" constriction combo is sort of like the .30-06 of the rifle hunting world, a proven standard by which all others will be judged by.