TEN
Clara Oswin Oswald
Despite only appearing on screen twice, and neither of those 'officially' as companion, I can't help but have a good feeling about this one, and so coming in at tenth place is Clara Oswin Oswald.
There is something about the character I find intriguing. Moffat has a tendency to over confuse and draw things out and Clara has begun life in much the same way, but rather than feel annoyed at it happening again, I'm actually genuinly intrigued by the character and how she will play out.
Characteristically there is no guarantee that we have even seen the real Clara yet, but from her (so far) two appearances there has been a certain consistency that I am sure will play out through the rest of her time on the show. She has a cheeky charm about her and her fascination with the Doctor and playful banter that comes of it has been great to watch so far. I think they are going to make a very interesting pairing and her more playful personality will be a breath of fresh air after having quite a serious companion in Amy Pond (who got bumped to 11 for Clara).
It may be premature to include her in one of these lists and my opinion could very likely change as we see more of her, but for now I am happy to include her in tenth place.