I like followers, especially when I play DiD/Ironman. They make me feel less lonely and protected in dungeons and when exploring, because I know they've got my back. It also feels more immersive and realistic, having a follower with you, because how many of you would enter a Nordic Crypt alone if that sort of thing existed in real life. I for one would take as many followers as I could. I loved Final Fantasy 1 where you could pick for fighters and have them all support each other.
My favourites would be Cicero, Serana, or Teldryn Sero. Cicero for his character and general insanity. "Let's kill someone!" Or "Ooh listener, that tickles!" Lol
Serana because she acts like a normal person (except she's constantly bitching "Lets get inside" and when we're in a cave "I've spent more than my share of time in caves already". Make your freaking mind up woman!
And Teldryn because he seems to me like the most realistic mercenary, telling you about previous employers and exploring and commenting on where you are.
Cicero is a Dark Brotherhood assassin, Serana is a Necromancer vampire, and Teldryn is a mercenary.