Federal Law Enforcement 00Buck, low recoil with the 'flight control wad'. Shot great out of my 870 and didn't punish my shoulder too badly.
It's the Federal LE13200. 9 pellet 00 buck. Bought from SGAmmo or Bonefrog Gun Club. I can't recall which.
Same results with the equivalent slug round.
I've killed nothing but cardboard with it, but very satisfied with it at the range. Downside is that it is more expensive than a #7 or something from Walmart.