MR SMITH, I NEED YOU! *cue fanfare of awesomeness*
In The Sarah Jane Adventures in "The Last Sontaran, part 2" Kaagh has the regulars trapped with no forseeable way out of the situation, when Chrissie Jackson runs in, and jams her siletto into his probic vent (the vent on the back of his neck, a Sontaran's only weakness) stunning him.
Chrissie: Try my size five, humpty!
In The Wedding of Sarah Jane Smith, Clyde Langer walks right up to The Trickster, grabs him by the hand and actually hurts him with a fistful of TARDIS energy.
On the subject of the wedding, you have to give props to Peter who knowingly condemns himself and saves everyone else by withdrawing from the Trickster's contract.
The delivery of the lines were also quite awesome.
Our favourite Snarker gets to trick two Men in Black robots to blow themselves up . Afterwards picks up their shades and utters.
Clyde : Hasta La Vista, baby
In Lost In Time, Clyde ends up stranded in WWII-era Britain, and delivers his Badass Boast after being captured by the enemy. 'I've taken on bigger loonies than you. I've taken on hideous bud-eyed monsters, and defeated them all... with this...' Thus does he succeed in both intimidating a bunch of armed Nazi soldiers with his loudly-blaring iPod, and giving his friend a chance to grab the MacGuffin, after which they make their rapid escape.
The Mad Woman In The Attic: Clyde and Sarah Jane are questioning the caretaker of an abandoned amusement park while looking for Rani. The caretaker pretends that he'd never met Rani, so Clyde starts talking about how stupid and worthless Rani is. Appalled at Clyde's rudeness, the caretaker says that Rani seemed like a nice girl when he'd met him, revealing that he had in fact met Rani. This bit showed that Clyde is more than just the comic relief or the "cool kid." He can actually be really clever.
"I'm not past my sell-by date yet!" - Sarah Jane.
Let's face it. This entire series is one Crowning Moment for Sarah Jane after another. After all, she's frakking Sarah Jane Smith!
This series is also a meta-CMOA for Elisabeth Sladen herself. After all, what other actor has come back to a show thirty years after they left and, in the course of forty-two minutes, reminded everyone just why they loved that character in the first place, becoming such a smashing success that they earn their own spinoff?? What a woman she was!
The Brigadier himself gets one in Enemy of the Bane, when he effortlessly and unflinchingly takes down an attacking Bane with his cane.