A/N: Here is that other thing I was talking about. It was written between the hours of 4am and 5am. I tried to edit it... Also, small spoilers for Waters of Mars.
Anyways, it's basically a "I love David Tennant's acting so flipping much, here is why he's amazing" study of the last few episodes of season 4. Yes, I am a Ten fangirl, but I like him for much more than his looks. Read below to see why he's so amazing.

I love David Tennant so much because he can be all cute and nice and dorky and funny, but he can also be sad, and angry and scary and villainous. He has such a wide range of emotions and that is what makes him so good. Other actors always do happy and funny or sad and angry but usually not straying outside of what they are good at.

David Tennant as the Doctor was really nice and funny, with some sad moments, but those sad moments made him kind. Then as time went on, he became more cynical and bitter and the sad moments just made him angsty, not kind. He got worse when a companion left, but then the next made him better. Then, when he needed one most, there was no companion to stop him and he crossed the line. He tried to take time into his own hands and be a god.

Luckily, he had a person there to remind him of what he should be, what he needs to be, even at the sacrifice of her own life. When she kills herself, it's a wake-up call to the Doctor that not all of his decisions are the right ones. And so he runs away. He knows that he will die soon, but he tries to postpone it as long as possible. But when he eventually faces it, he finds that he's still not ready, despite all the mistakes and dark feelings, he's not ready to die.

David Tennant really portrays it well. When he's talking to Wilf in the café, there is a brief moment of lost composure, but it is quickly buried. Also, in that scene, all I can see is a father and son, perhaps helped by the conversation in the spaceship where the Doctor says "I'd be proud… if you were my dad" and I can see that he is relying on Wilf as a sort of father, even though he's hundreds of years older than him.

Then in the final scene after the Doctor oscillates between killing the Master or Rassilon, which was also very intense and we all thought that the Doctor was going to use a gun on someone for the first time, we see his relief at being alive. That little half-sob, half-laugh and huff of "I made it, I'm still alive" fades as he hears the four knocks and it turns to horror. Then there is that little smile when Wilf says "Just leave me". The Doctor already knows that he won't leave Wilf. Prophesy or not, he feels he has a duty to save him, even at the cost of his own life. That's what that smile means.

Then he goes through his rant of being more important than Wilf, and rants against the unfairness of death so soon after his big victory, calling it his reward. Then he stops and thinks about what he just said and how it goes against all his morals and realizes "I've lived too long". He knows he has to change because this Doctor is too dark and willing to cross the line. He makes peace with it, almost. He tells Wilf its an honor to save him and then he gets hit with the radiation.

This scene is particularly amazing because you can see he's in pain, yes, but lots of characters show pain. David Tennant shows the Doctor fighting against the pain. He sort of gets up after the first wave and looks at the door, almost hopeful that he can get out before the radiation gets too strong for even him to handle. Then you can see the hope die as another wave of pain hits and he can't even support himself. He slowly collapses to the floor and then, in the most powerful gesture, curls up. He curls up and grabs his hair. This is perhaps the most vulnerable position of pain I have ever seen. It's broadcasting the pain so much better than just a grimace or tense body. He grabs onto his hair because it hurts so much, he needs a different kind of pain to distract him. It's almost childlike, the position. And then the radiation shuts off and he's still curled up. It still hurts because he just absorbed so much radiation into his body and it is literally killing him, cell by cell. But then he uncurls and gets up anyways. He knows he's dying but is still putting it off.

He held off on regenerating for as long as possible, almost too long, and through all that time, he never showed pain until the end. And then he just needs to get to his TARDIS. He knows that holding it in would make it too strong to be around fragile buildings so he needs to make it into the TARDIS to protect everyone else. He keeps holding his regeneration in to get the TARDIS off earth to make even more sure that he doesn't hurt anyone. And then he knows he can't hold it any longer but he still tries, making it go slowly, and just before he loses control of it, he delivers the final line, "I don't want to go."

This is so sad because he is still holding his composure, even though there is no one there to see him. He's still being brave because he has to be, because he's dying. And he goes away and we are left with someone who is decidedly lighter hearted than the Doctor we just left. This Doctor, already we can see, hasn't lost anyone yet. He's a brand new personality that won't let him get as dark as David Tennant Doctor.

Drop a review if you liked it, feel free to PM me to squeal about David Tennant.