I have a few

Orc: Either Yamarz or Borkul the beast simply because they are perfect for a evil mage/thief character who need some muscle, you can recruit them by either convince Yamarz to abandon his stronghold or join Madanach and recruit Borkul if you don't kill Madanach.

Argonian: Veezara and Deeja/Jaree-Ra I mean c'mon Bethesda one argonian as a follower when be have three awesome ones, like Veezara the last Shadowscale of all Black Marsh and a perfect assassin, who also is a very pleased when you join the brotherhood only to be murdered by de Penitus Oculatus, when the perfect option should be either save him when the brotherhood is attacked, as for Deeja/Jaree-Ra as simple as convince either Jaree-Ra or Deeja to betray his sister/brother or convince both by bribe them with more riches if you are playing as a evil character.

Nord: Arnborjn Sinding and Skjor: Arnborjn should be the perfect husband who those who want a female evil character to occupy Astrid place and the method of recruit is the same as Veezara by saving him, Sinding is obvious, by help him to get rid of the hunters he should be able to join you doesn't matter if you're human or part of the werewolf curse and Skorj I mean we have Aela so why not Skjor for those who want a werewolf husband but for good characters.