It's too soon for me to have an opinion about Clara. Of course, I also missed most of the episodes that first introduced her, like the Christmas Special. I'd like for there to be some kind of deep plot behind her character.
The Doctor's monologue in "The Rings of Akhaten" is probably the best one he's given since the events around the Pandorica.
My favorite companion was probably Martha. Intelligent and capable of handling herself. Probably the one companion of the reboot who didn't strike me as utterly dependent on the Doctor for everything.