Donna, easily.

It was easy. Graham. Just because I like others much more.

@Master P Koon That's exactly why I voted Ace. I love Graham though.

Graham seems to be the most disliked, but since I don't know who that is, I went for Ace. She wasn't too bad in the tv series, but in the novels she's very unlikeable.

@Shambala108 So you haven't seen the new series (11, 12, 13) with the 13th Doctor? I must ask why.

@Shambala108 Graham is the companion played by Bradley Walsh who travels with the 13th Doctor. He's in series 11 and series 12.

@DoctorRey12 it's too long an answer to post here, but to sum up, life's too short to waste on anything I don't really like.

Easily Graham - I never really liked him at all. Not sure there’s much else to say really.

It was a tough choice between Graham and River. I don't dislike either of them, but the others are four of my favourite companions so I was hardly gonna choose any of them. I ultimately chose River, because at least Graham didn't have a forced love story with the Doctor.

Well crap, I accidentally voted for Noble whilst thinking this post was about which character you like the most. :p