What Would Be The Best 12 Gauge Shotgun Shell For Close Combat 10-25 Yard In Your Opinion?

Any buckshot #1 or larger will work well. The best shell is the load of #1 or larger buckshot that patterns tightest out of your gun. Generally, this means Federal 00 Buck with the Flight Control wad. Low recoil is preferable, because it still has plenty of energy, but allows for faster follow up shots.
If I could design my own perfect load, it would be 10-12 pellets of hardened, plated #1 buck, as well as plenty of buffering material, all packed into a flight control wad. This would give me a tight patterning low recoil load with an additional 1-4 pellets over the average low recoil 00 shell, while still offering large enough pellets to insure sufficient penetration. Unfortunately, Federal has not built such a load, so the best currently available are the federal 8 to 9 pellet low recoil 00 buck with the flight control wad.