ok, I spoke to the Hubbs and he said it depends entirely on the distance that you're shooting and whether or not you are using a shotgun with a rifled barrel or not.
for longer distances & rifled barrels he suggests any of the sabot slugs from the big manufacturers like winchester or remmington, he thinks the copper ones are marketing gimmicks and regular gilded hollowpoints are just fine.
for shorter ranges he prefers regular old 1oz 12g soft lead slugs.
he also wants me to reiterate that this is just for your common North American White-Tailed Deer. Anything bigger or more substantial and it'd be a whole different discussion.
His all-time FAVORITE slug in GENERAL however, since you mentioned favorites, is the Dixie Terminator. He says it'll kill aaaaaaanything you need to drop. Rhinos and Zombies included.