"You look at me and you can't see me, can you? Please, just see me." - Best Scene in the Series (so far!)
The scene at the end of Deep Breath where Clara accepts 12 is so far for me. I see Matt Smith's cameo get all the hype, but it's really Capaldi and Clara who carry the emotional core of it and sell the moment. Capaldi not being outraged, or disapointed, in a state of melancholy as he realises Clara doesn't see him still is heart breaking. He is so calm despite his emotions, and the way Capaldi paces like 12 wants to not be in this situation but does want to be with Clara is great. The look Jenna gives as she slowly walks over is beautiful. She takes hims eriously and carries all the tension of the scene on her back until she smiles and it all fades away.
I got started on Doctor Who with Eccleston and RTD when I was like 6, and only a month ago watched Capaldi's run for the first time. It truly is an absolute great run and this scene is one I cannot forget. The emotion hits so well.