Oswin spends a year trapped in a Dalek insane asylum, baking soufflés.
The Doctor: How are you doing that, eh? This is Dalek technology. Oswin:[nonplussed] It's very easy to hack. The Doctor: No it isn't!
The Doctor has a roomful of Axe-Crazy Daleks coming at him. How does he deal with this? He notices the front one has no weapon, so he provokes it into activating its self-destruct as a way of killing him, and then starts fiddling around with its machinery. The Dalek tells him the self-destruct can't be stopped. He replies he wasn't trying to, he was looking for "reverse." The Dalek then starts helplessly reversing, straight into its comrades, and the unstoppable self-destruct goes off, clearing the room. Later, Rory goes through the same room, and we get the exchange that puts the cherry on top:
Rory: Who killed all the Daleks? The Doctor: Who do you think?
Early in the episode, the Doctor states his intention to fix Amy and Rory's marriage, which Amy declares is "not something you can fix like your bow tie." Later in the episode, the Doctor maneuvers events so that the Ponds' fix their own marriage. Cut to a shot of the Doctor, adjusting his bow tie, as if to say "challenge completed".
Oswin resisted Dalek conversion of her mind and held on to her humanity for at least a year. And she did it well enough she genuinely didn't realize what had happened until the Doctor forced her to. Even when she does realize, she keeps hold of her humanity long enough to take down the force field.
Rory has a chance to show off his nursing skills. His father's been shot by a robot's laser but he's all patched up and feeling fine moments later. He also gives the robots a Tranquil Fury warning that makes them (comic relief throughout the rest of the story) nervous and back off.
In his first appearance, the Unfazed Everyman, Brian Williams, decides to pilot the spaceship even though he doesn't fully understand it.
Amy and Riddell vs a pack of hungry Raptors.
Riddell: Dinosaurs ahead, a lady at my side, about to be blown up. (smiles) Not sure I've ever been happier.
The Doctor refusing to help Solomon off his ship before sending it off to be hit by missiles in a Karmic Death.
The Doctor: Look, Solomon. The missiles. See them shine? See how valuable they are. And they're all yours. Enjoy your bounty.
The Doctor’s sheer fury towards Jex after discovering what he did during his planet’s war.
During the Gunslinger's hunt for Kahler Jex, Jex flees to his spaceship outside of town. Instead of escaping into space just as he and the Doctor planned, he decides then to set his ship to self-destruct to atone for his past mistakes and end the Gunslinger's vendetta.
After Kahler Jex dies, the Gunslinger feels he is but a weapon without a purpose and decides to go self-destruct in the desert. The Doctor convinces the Gunslinger otherwise and makes him the new Marshall of Mercy, complete with his very own badge and a new-found sense of purpose.
Isaac, the Marshall of Mercy, is everything that the Doctor has ever hoped to see in humanity. Here's a man who runs a town where all are welcome, regardless of race, color, creed, planet of origin, or past misdeeds. He barely even knows the Doctor, and still performs a Heroic Sacrifice to save him.
While it's Played for Laughs more than it is for awesomeness, the fact that the Doctor was able to paint a fence, mow the lawn, vacuum the house, rewire a car, and bounce a soccer ball 5 million times in the space of an hour deserves a mention.
Rory effectively decides to Screw Destiny by committing suicide. Not only does it work, he knows that he'll come back because he always comes back.
The TARDIS landing in Grayle's house. For Grayle, it's something out of horror movie, causing the lights to go haywire, and the building to shake, while strange noises happen. Made more awesome with River's line (and Murray Gold's soundtrack) when the TARDIS makes the landing attempt, culminating in it crashing into the foyer, sending Grayle flying.
River Song: Oh you bad boy, you could burn New York.
Amy could stay with the Doctor and River, and know where she is, but with no guarantee where she will end up she bravely accepts the risks to try to be with Rory. Not only does it work, but she finds a way to let the Doctor know she was successful.
The Doctor's Big Damn Heroes moment, using a Mr. Punch puppet to assist him.
The Doctor:[as Mr. Punch] Doctor? Doctor?! Doctor... Who?[blasts the Ice Governess with his sonic screwdriver, causing her to shatter]
Strax spends most of his time as a bumbling sidekick whose solution for every problem is violence. But when the snowmen start their attack, he gets the opportunity to show just how good a military tactician he is.
Just look at how beautiful and fabulous the TARDIS looks now! She's got spiny things now. The Doctor might be in mourning, but he's still a man-child and she's trying to cheer him up.
Clara uses her recently acquired Hollywood Hacking abilities to bypass the computer security of the Big Bad and instead use the lower-level security of the laptops to snap shots of all of the employees, and then use facial recognition software to locate their social media presences and from those, their place of work.
The Doctor, or rather a Spoonhead copy of him, riding a motorcycle up the side of the Shard
The Doctor's Rousing Speech to Merry about how she's a unique combination of elements millions of years in the making.
"Hey. Do you mind if I tell you a story? One you might not have heard. All the elements in your body were forged many many millions of years ago in the heart of a faraway star that exploded and died. That explosion scattered those elements across the desolations of deep space. After so, so many millions of years, these elements came together to form new stars and new planets. And on and on it went. The elements came together and burst apart, forming shoes and ships and sealing wax and cabbages and kings. Until, eventually, they came together to make you. You are unique in the universe. There is only one Merry Galel. And there will never be another. Getting rid of that existence isn't a sacrifice, it's a waste!"
At the climax, the Doctor tries to defeat the sentient planet by force-feeding the parasitic sun over a thousand years' worth of his bad memories, and gives a speech of epic proportions about the many terrors he has seen in his long life.
The Doctor: Oh, you like to think you're a god, but you're not a god! You're just a parasite eaten out with jealousy and envy and longing for the lives of others. You feed on them. On the memory of love and loss and birth and death and joy and sorrow. So... so come on, then. Take mine. Take my memories. But I hope you’ve got a big appetite, because I've lived a long life, and I've seen a few things. I walked away from the Last Great Time War. I marked the passing of the Time Lords. I saw the birth of the universe and I watched as time ran out, moment by moment, until nothing remained. No time. No space. Just me! I've walked in universes where the laws of physics were devised by the mind of a MADMAN. I've watched universes freeze and creations burn. I have seen things you wouldn’t believe. I have lost things you'll never understand! And I know things. Secrets that must never be told. Knowledge that must never be spoken. Knowledge that will make parasite gods BLAZE! SO COME OOOOON THEN! TAKE IT! TAKE IT ALL, BABY! HAVE IT! YOU HAVE IT ALL!
While the Doctor is giving this magnificent speech, Merry and all the people sing a hymn to help him quell the sentient planet. It is glorious.
Despite this, the Old God is still hungry. What does Clara do? Makes it implode by force-feeding it a leaf. A single leaf containing the memories, hopes, and dreams of her mother, proving that though the Doctor has a plethora of memories to feed off of, nothing beats the infinite possibilities of the many could-have-beens of a single person.
The Doctor needs someone who isn't a soldier to negotiate with Skaldak. Clara clears her throat and points out that she's willing to negotiate with a hostile alien warrior, by herself, and talks the Doctor into letting her do it.
Professor Grisenko and Clara are cheerfully chatting together when Skaldak grabs Clara in its claws, and Grisenko instinctively Blast at Skaldak with his .357 magnum revolver, forcing the Ice Warrior to let go of her.
Clara persuades the TARDIS to help her fly into a collapsing pocket universe to save the Doctor. It's especially impressive because, at the time, the TARDIS didn't like Clara very much.
The Doctor forcing a rather ruthless bunch of scavengers to help him search the TARDIS for Clara.
The Doctor: I just activated the TARDIS self-destruct system. One hour until this ship blows. Don't try to leave, the TARDIS is in lockdown, I'll open those doors when Clara's by my side. Bram: You crazy lunatic! The Doctor: My ship, my rules! Gregor: You'll kill us all, and the girl. The Doctor: She's going to die if you don't help me. Don't get into a spaceship with a mad man, didn't anyone ever teach you that? OK, a little gentle persuasion. Say, 30 minutes. [shortens the countdown] Bram: We'll die even quicker now! The Doctor: You'll perform better under pressure. Anybody wanna go for 15 minutes?
Made even better by the later revelation that he's bluffing, and the TARDIS still doesn't have a self-destruct.
The TARDIS creating a couple of echoes of the console room to save Clara and the Doctor, keeping them in the safest rooms until Clara accidentally lets one of the zombies in.
Ada beating the Red Leech that ruined her life to a bloody pulp.
Ada getting the courage to stand up to her mother. She screams at her and even goes so far as to beat her with her cane. It's both terrifying and incredibly therapeutic.
Ada rescuing the Doctor from the "reject pile". She knows perfectly well that her mother would hate her for it, and her mother's opinion of her is the only thing she cares about — but she saves him anyway, not even knowing who he was.
Ada, at the end, being brave enough to not let her mother's tyranny ruin any more of her life; she's going to do something with her life, and has even found enough confidence to refer to herself as a "bright young lady" whereas before she had only ever called herself by derogatory terms.
Strax has two Big Damn Heroes moments in "The Crimson Horror," first charging a bunch of mooks with a laser gun while laughing like a maniac, then appearing at the top of the chimney to order Mrs. Gillyflower to stand down.
The Doctor puts up a Psychic Block Defense good enough to hold off the entire Cyberiad, before defeating "Mr. Clever", a Cyber-Planner that had taken over half his brain, by playing chess.
This needs to be emphasized—he's able to keep control of 49.881% of his brain, the exact same amount as the Cyberiad. The entire processing power of the Cyberiad is only just barely equivalent to the Doctor.
Clara taking command of a military unit and holding off the Cyberman for the entire episode.
The Great Intelligence pulls off a Batman Gambit that leads him to the Doctor's final resting place. Instead of a corpse, the Doctor leaves behind an open rift of temporal energy that represents the whole of his timeline. The Great Intelligence then steps into that burning white light, destroying himself and nearly erasing the whole of the Doctor's life with him.
Clara jumping into the Doctor's timestream, reincarnating herself throughout time and space to protect him from the Great Intelligence. Among other things, she advises the First Doctor on which TARDIS to steal. To save her, the Doctor jumps in after her, crossing his own timestream. The Expanded Universe book The Forgotten Son eventually revealed that Clara's success at thwarting him caused the Great Intelligence to jump ship entirely.
Doctor Who has an unprecedented Continuity Cavalcade in this episode, showing all of them as Clara and the Doctor travel through the latter's timeline]. This culminates in the big moment of the episode, where it's revealed that John Hurt is playing another incarnation of the Doctor, one who performed an act so reprehensible that the other Doctors refuse to acknowledge it.
The War Doctor's reveal. Dramatic and incredibly shocking. Just when everyone thinks there are strictly 11 Doctors out there to this point... we learn there is one more... who is not using the name that has been central to the show for 50 years. People's assumptions that there couldn't be any others are completely shaken. And his lines indicate that it was for a good reason.
War Doctor: What I did, I did without choice. Eleventh Doctor: I know. War Doctor: In the name of peace and sanity. Eleventh Doctor:But not inthe name of the Doctor!
. For Grayle, it's something out of horror movie, causing the lights to go haywire, and the building to shake, while strange noises happen. Made more awesome with River's line (and Murray Gold's soundtrack) when the TARDIS makes the landing attempt, culminating in it crashing into the foyer, sending Grayle flying.River Song: Oh you bad boy, you could burn New York.