In the first episode "Pilot", sticking his arm down a wood chipper.
Managing to pull a man loaded with Kryptonite and Lex Luthor up a catwalk with one hand in "Jitters".
Dodging a bullet for the first time in the episode "Rogue".
Taking out Ryan's abusive father with a bowling ball in the episode "Stray".
Diving into a tornado to save Lana in the episode "Tempest."
Jonathan gets one in the Season 2 premiere when he sneaks up on and tackles Roger Nixon when Nixon tries to abduct Clark (using kryptonite).
Shooting a bullet out of the air with heat vision in the episode "Heat".
Jumping from one building to another in the episode "Insurgence".
Beating up the three super-powered gang members, who were all stronger than him, in the episode "Witness".
Martha gets a particularly awesome one in "Heat" when she confronts a Brainwashed and Crazy -via-love pheromones Lex and lays the smackdown on him for sending Clark to jail for a crime he didn't commit just because his black widow wife Desirée has told him to:
Martha: ''You know Clark. He's not a criminal. He's the one person who's stood by you no matter what. Ask yourself, is he really capable of this?
Lex:I wouldn't have thought so. But I know my wife.
Martha:*speaking for herself and the viewers*Lex...you met and married her in a week. HOW WELL COULD YOU KNOW HER?!
Running to the other side of the forest and catching a villain's lighter before it could hit the gasoline trail in the episode "Slumber".
Tossing a lead-based paint can, while using his heat vision to disable AliciaBaker (who was weak against lead) from killing Lana, in the episode "Obsessed".
Special mention must be made of the man playing young Grandpa Kent in the flashback bits of "Relic", who went the extra mile and nailed all of Jonathan's mannerisms while looking just slightly and sounding very different from him. Taking the idea of genetic memory presented in the story somewhat literally.
Flying for the first time, albeit while brainwashed by Jor-El, in the episode "Crusade".
Throwing the football, running over to Mxyzptlk and saving Chloe from him, then running back to his original position without anybody noticing in the episode "Jinx".
"We can withstand anything you bring down on us... because we have each other. That's what will always separate the Kents from the Luthors. Now why don't you ge— why don't you get the hell off my property?"
Unfortunately, the stress of it all gave him a heart attack and he dies. Also, while Lionel could care less of Jonathan's little speech, he wasn't trying to blackmail him, but to help the Kents.
After being forced to Kneel Before Zod, tricking General Zod into touching the crystal that sends him back to the Phantom Zone in the episode "Zod".
Unleashing his Unstoppable Rage and defeating Titan in the episode "Combat". Bonus points that Titan is a wrestler who goes by the name of Kane.
Punching Bizarro into a powerline tower on the horizon, then later punching Bizarro into space in the episode "Bizarro".
Vaporizing a flash flood brought on by a breaking dam with his Heat Vision in the same episode.
Catching Kara's ankle and slamming her back to the ground in the episode "Kara".
Beating the shit out of Brainiac in the episode "Arctic".
Jimmy Olsen beating up a secret agent in the episode "Sleeper".
Chloe becoming the Watchtower in Hex.
Tess Mercer, Lex's former VP and acting CEO of LuthorCorp in his absence, discovers in the episode "Bulletproof" that, far from trusting her, he spies on her every waking movement. All this, despite the complete and unswerving loyalty she'd given him throughout the years. She hits back with the following speech:
"When I thought my life was over, you gave me a reason to keep going. I wouldn't be who I am without you. I trusted you, because I respected you. I've done everything you've ever asked. You've seen that with your own eyes and, apparently, with mine. But not anymore. I hope you watch with rapt attention as your bank accounts close, as you lose all contact with the outside world, as your life disappears before your eyes. Goodbye, Lex. (jams his spyware) I loved you, you son of a bitch."
And as a final parting shot, she then proceeds to merge LuthorCorp with Lex's rival, Oliver Queen of Queen Industries. Ouch.
Lex finally freeing the show from Lana with his brilliant kryptonite bomb trap. See, in the last episode Lana stole the Prometheus Project's Super Suit right out from under Lex, despite it never showing exactly how she found out about it, thus granting her God Mode powers. However, it turns out that the suit was designed to absorb Kryptonite. Cue a sadistic choice on top of the Daily Planet Building: Either Lana absorbs all of the Kryptonite to stop the bomb, thus ensuring that she'll be so irradiated by the Kryptonite that she can never get close to Clark again without killing him, or they do nothing and watch the city burn in the explosion. Lana sacrifices herself and leaves. The best part? Lex was on life support and confined to a van when he came up with this plan. Magnificent Bastard indeed.
That one is obviously only "awesome" if you actually hate Lana ...
Major Zod forcing his rebellious army to kneel before him without his powers in the episode "Savior".
His Knife Fight with Major Zod in the Season 9 finale, "Salvation", likely counts as one for both combatants, the coreographers, and the show as a whole. That was a truly epic finale.
Be honest, who's jaw didn't drop when Clark decided to avert the Bad Future by destroying the Solar-Towers in "Persuasion".
Dr. Fate in "Absolute Justice":
His transformation sequence.
Restoring John Jones' abilities.
"It is not your fate to die this day, Martian!"
And, of course, John's badass boast when he uses Them on Icicle:
"I'm Mars' sole survivor. There's a reason for that."
Conspiracy, when he flies for the first time.
And also in Upgrade when he blew up a truckload of kryptonite and swooped down from the skies and landed in front of Clark. Let's just forget he is the villain for the moment and admit that it is plain awesome.
In Sacrifice when he burns down the entire Checkmate castle. After all the plotting, all the shady dealings, all the spying and kidnapping, Zod reminds everyone even that is no match for world-shattering raw power.
Tess gets another one in "Salvation", the Season 9 finale, when she goes and stands up to a fully-powered General Zod in the Fortress itself, armed with brass knuckles made of Green K. Sure, she gets roasted by Zod's heat vision and seemingly dies for her trouble, but damn if it wasn't awesome.
The Lex Luthor clone gives Clark a Sadistic Choice in the episode "Lazarus". Save Lois Lane from being burned alive, or save the people of Metropolis from the falling Daily Planet globe. Clark does both, and catches the globe by flying.
Clark FINALLY taking flight in "Collateral", holding Lois in a true Superman moment ... shame it was All Just a Dream caused by the Vigilante Registration Act's computer systems. But to do it, he had to overcome the same mental hangup that's keeping him from flying in real life.
One for Oliver, Tess and Lois managing to battle Ultraman and survive until Clark dimension-switched them back in "Luthor".
This one isn't only impressive because the three of them are powerless. When the episode leaves E-1, Lois is presumably unconscious, Tess has about five seconds to give Ultraman the universe-switching box before he kills her, and Oliver isn't even there. By the time Clark gets back, Oliver's there, all three of them have Kryptonite weapons, and the only apparent remotely-serious injury is Lois's broken arm, which she gets in the first two seconds of the fight.
Hawkman's last-second aerial rescue of Lois, while dying and on fire. Badass.
Which was preceded by his fight with Slade — true, it was short, but it was so very awesome.
Chloe surrenders herself to the Suicide Squad in order to secure Oliver's release, and apparently kills herself while in their custody. But after the League is captured during Carter's funeral, the Squad comes to their rescue - with Chloe! Chloe Sullivan managed made the freaking Suicide Squad her bitch!
The brutal fight between Clark and Oliver in "Dominion". It's a bloody, no-holds barred affair, which ends with Oliver stabbing Clark. Zod goes into check what happened... and Clark grabs his crystal, porting himself and Oliver home. That's right: Clark, the Big Dumb Alien, managed to outfox General Zod, one of the top Chessmasters on the show.
"Finale", being the Grand Finale, naturally has plenty of moments:
First off, the image of Apokolips approaching Earth is pure win.
Near the end of Part 1, Clark manages to appeal to the good still in Oliver, who manages to overcome Darkseid's corruption.
Tess is captured by Lionel and Strapped to an Operating Table (literally), about to have her heart removed to complete Lex's perfect clone. She then proceeds to knock over a Mook, grab a scalpel from his surgery tray, use it to break free, and then mow down the rest of the Mooks. And then she shoots Lionel and walks away, leaving him for dead.
The Dark Prophets are gloating about their arriving victory... when in walks Oliver, in full Green Arrow regalia. The Prophets gloat about how he has no chance of defeating them — and before they have a chance to do anything more pose threateningly, he fires three arrows at once, hitting all of them simultaneously, banishing them.
Clark is confronted by Darkseid in Lionel's body and is thrown across the room. As he's flying, Jor-El grants him a vision of all the trials he's faced — essentially a two-minute montage of his greatest moments from the past ten years, accompanied by a remix of the classic Christopher Reeve theme song. As the vision ends, Clark stops himself in midair, and proceeds to fly through Darkseid, ripping him out of Lionel's body and dispersing his essence.
Tess goes to LuthorCorp and confronts Lex who fatally stabs her. However, before she dies, she exposes Lex to a toxin that completely wipes his memory of — at the very least — everything that's happened since he came to Smallville.
This is followed Lex walking to the office window, and we get an exterior view of the LuthorCorp building, just as a shockwave from the approaching Apokolips hits it, making all the letters between the "L" and the "C" shatter and fall off, the damage to the building making it look like there's an "E" and "X" in their place; effectively changing the name of the company from LuthorCorp to LexCorp.
Clark flies for the first time of his own free will, switching into THE costume mid-flight. He then proceeds to catch a falling Air Force One and correct its flight, and then he pushes Apokolips out of Earth's orbit, which inspires enough hope to remove Darkseid's taint from all of humanity.
And, finally, there's the Distant Finale. Not only does it show a very well-developed Smallville version of the set-up in the comics (specifically, things at the Daily Planet), but it, along with the series, ends the only way it could: Clark running out onto the Daily Planet's roof, ripping open his shirt to reveal the S-shield beneath as he prepares to take flight, the camera focusing on that iconic symbol as the classic theme song plays magnificently in the background.
With the credits 'swooshing' in the style of Superman: The Movie. The 'swooshes' were what did it for me.
Oliver gets one by shooting a Kryptonite dart into Zod whilst the latter is super-speeding. Although Zod wasn't dodging it - he seems to not realise that it is tipped with kryptonite. And Oliver gets branded with heat vision for his trouble.
Ollie gets one in his first appearance on the show: he launches an arrow from his office to the Daily Planet globe, landing on a country on the globe.
"You say you're saving the planet, but you really only care about yourself. You figured out Maxwell's charade because you know in your heart that Oliver's declaration of love was a lie. You can't comprehend what it means to truly protect someone you love. And stay away from Clark Kent. If you're not careful, you'll end up on the wrong side of the coming apocalypse."