For me, it would have to be Mjoll. She just never shuts up and tells the same stories over and over again in that terrible accent of hers.
Also, I'm not a fan of Lydia and her attitude sometimes. "I am sworn to carry your burden... D:<" I am a fan of her looks though.

What do you guys think?

You picked the two I like the best, lol.

My least favorite that I have used is J'zargo...I sacraficed him to Boethiah.

Aww... I kind of like J'zargo. He's following me now. I'm still wondering who I want to sacrifice.

Lydia.

She just sounds like she wants to stab me in the throat all the time.

Wouldn't you be [censored]y if you knew if Dovahkiin viewed you as nothing more then a meat shield and a pack mule?

Barbas

He had one of the best voice-overs in the game. Sure, he kinda was always in your face, but still. I thought he was cool.

Dead Thralls. No? Live ones? OK.

Lydia.

I loved Barbas! His voice was awesome, but he did get really annoying with all of the pushing and charging into battle :/

He has the ability to be the best destruction melee fighter in the game, yet all he does is use firecrackers...

Also, he tried to kill me with his scrolls. So, I had to show him what was what.