I don't know what it is, but Donna just irritated the everloving crap out of me.
Yes to this. I'm not a fan of her standup comedy either. She's an annoying shrill whiny bitch.
Other then that, I've liked every companion and all 3 Doctor's since 2005. I didn't start watching it until the 11th but then I went back and watched them all until I caught up and I've been watching them ever since.
I like each of them for their own reasons.
I like the 9th intensity and his interactions with Rose really got me hooked on the concept of the companion.
The 10th was good all around but his companion hoping and eventual crash landing into Donna turned my stomach. (I really liked Martha.) I was also upset with the show for losing Rose but I suppose it had to happen.
The 11th is my favorite because of his quirky goofy personality. He keeps me laughing, although I have a hard time sometimes taking him seriously when he makes his "intense" face. Also, I really liked Amy a lot, she was fun.