Who is the best deuteragonist in your opinion?

I think he is from . I know that maybe you could think any members of the crew could be his deuteragonist since he doesn't appear in all episodes but he is a very well written character. He always care of House even this one tries to anger or show him "the truth". He has suffered a lot, both from House and the life itself but he has gone throuth all that shit and become stronger. Also he has a cat.

I haven't finished it yet so no spoilers please.