5. River Song, 11th Doctor's Wife (Companion Once In A While)
I don't know if River is technically considered a companion, but she did spend a great deal of time with The Doctor so I think she's definitely a companion. She is the daughter os his companions Amy and Rory and first meets with The Doctor back in the 10th Doctor years. She's got sass, beauty, cheekiness, and never-ending love for her husband. She never wanted to hurt him in any way. She even held herself together when her parents Amy and Rory were taken to the past by that Weeping Angel. She seems like she'd be the kind of friend to sleep over and take you somewhere to rob a place and do it in the sexiest and most cheekiest way. She's the bad girl with never ending love friend.