POTD w/extra difficulty mod, so my totals might be higher overall since enemies have more health (but I didn't do nemnok, vampires, or all exploration).
Watcher: 173,897 - 2004/3950 crit/hit - dual pistol monk/ranger using crit talents but purposefully avoiding infinite blunderbus stuff by using pistols.
Aloth: 47,779 - 8m18d - Rogue/Wizard buffing self and going melee - . Also took the most damage and got knocked out the most, wonder why... ;-)
Maia: 49371.9 - 5m8d - Scout using soulbound arquebus
Pallegina - 11,017 - 5m17d - full tank spec, really low damage.
Xoti - 5830 - 4m4d - only used early game until her quest was done
Tekehu - 21319.9 - 3m11d - druid aoe attacks, also had highest single target damage at 239
Really surprised by how much damage others are getting out of their companions. I wasn't stealth sniping or using a ton of empowers or anything.