Voice in Victor Vran is, sadly, the best example I can think of when it comes to companions that I don't want to strangle, throw out a window, or otherwise mutilate in horrible fashion. All he does is offer ridiculously snarky and sarcastic comments, and it makes a very average Diablo-esque game quite entertaining at points. If you run away from battle too much he sings a song about how brave you are for running away. Pick up a weapon and he'll occasionally comment on it. He has something to say about pretty much anything, and most of what he has to say is so phenomenally trivial and unhelpful that it's actually quite funny. Too bad he isn't in a better game, really...although if he was he probably wouldn't be as amusing, because he KNOWS how utterly rubbish the whole thing is and takes a perverse sort of delight in it.
The Watcher in Darksiders III falls into a similar category, although her banter with Fury isn't as frequent as I would like. She also gets bonus points for being a companion that you actually get to kill.
Otherwise...yeah, no. It might be dangerous to go alone, but I'll take my chances. Death is preferable to someone trying to help you not die.