Bella,because she can block all mental and physical attacks and can project her shield to protect her loved ones and her friends,including the wolf pack.

He doesn't have to guess what someone is thinking.

I would love to have her power or Janes

I would hate to be able to read everyone's mind. Imagine how stupid some people are! And I would feel like I'm invading their privacy!
Zafrina's is awesome. I'd like that one, and Bella's too. Though I don't know when I'd find any use in Bella's. Wouldn't want Jane's, Alec's or Kate's and I'm not really interested in Alices' or Eleazar's.