In the fourth story mission, Trent and Juni having almost been killed by a Liberty Police officer, and now have to flee Manhattan before they can lock down all Trade Lanes. Their only means of escape have been blocked by capital ships, including the Battleship Unity seen two missions ago. When all hope seems lost...King and Walker have a Big Damn Heroes moment and blow up the Unity, allowing you to flee.
In another instance of Big Damn Heroes, Trent and Ozu have been captured by Tekagi after trying to steal the Proteus Tome. In a display of brutality, Tekagi draws a blade from his sleeve and throws it into Ozu's chest. Trent is about to get back at him, but then Tekagi's eyes start glowing and his voice becomes distorted. But before Tekagi can get him, Lord Hakkera comes out of nowhere and blasts the place with his ship's weapons. Trent grabs the tome and dives out the window into Hakkera's cargo hold. Tekagi is about to throw another blade at Trent, but then he notices the Not Quite Dead Ozu take out a detonator, which sets off the bomb he placed under the table, finishing off himself and Tekagi.
President Jacobi, who'd just been rescued, quickly grabs a weapon and blasts the Nomad coming out of the Chancellor's body.
Burn, you son of a bitch!
After an escort mission to Willard Research Station, you are attacked by three Rheinland Heavy Fighters. When Juni meets with the captain of a Liberty cruiser stationed in California, Willard goes mayday and you have to respond. Upon reaching the station, you are pitted against a huge battalion of Rheinland warships. Even Trent lampshades this in his logbook.
There's one point in the mission where you meet Sinclair where you are ambushed by the Rheinland Battleship Wotan. Before the fight begins, the two Rheinland deserters engage their cloaking devices, sneak up to the battleship and destroy it in one torpedo salvo.
Just about every instance of Big Damn Heroes. Whenever they happen, you are usually faced with a huge fleet that dwarfs you in size and power.
When two Rheinland agents are looking for you in Tobias' shop (please note that this line is voiced by John Rhys-Davies, and should be read in a thick Welsh accent for full effect):
Tobias: Listen to me. You are not in Rheinland now, you're in my shop. I've already told you that the man you're looking for isn't here, so unless you'd like to get an education in foreign policy that you won't soon forget, I'd suggest you move along! Now!
Made even cooler by the way that the menacing music that was playing when the Rheinlanders were talking abruptly cuts off as Tobias says this.
The end of the Bretonia arc has something along these lines:
Juni: Dammit! Rheinland is blocking the trade lane to Tau-23!
Trent: What are we gonna do then, Juni?
Beating that mission is also crowning moment for Trent, Juni, Outcast pilots that help, and the PLAYER (if you choose to actually fight and not running around, that is)! Really, since it's you with another 4-5 fighters against a battleship, 2 cruisers, and buttload of fighters and gunboats. Essentially, you're fighting against a fleet.
Later, Walker plows in his cruiser, packed to the limit with mines, through an entire fleet made of Liberty, Rheinland and alien fighters and capital ships. He dies in a blaze of glory:
Walker: "Goodbye, Jun'ko. Win this one for me!"
Botzler takes the cake here, with his Heroic Sacrifice that destroys 7 experimental battleships, by himself.
Slightly less badass, but still pretty damn awesome: during the attack on Tekagi's base, there is a battleship hanging over the arch, with enough heavy fighter coverage to reduce you to so much space debris in (literally) around two seconds, if you're unlucky enough. Battleships alone are perfectly capable of blowing you to smithereens if you make one false move. Also, that particular battleship you can take on by yourself and actually destroy. Oh, and there's two of them and a few cruisers when you're trying to retrieve the spy from Rheinland space—you can destroy them too, provided you have enough weaponry and time. The Odin decloaks right before you join up with the Order; with sufficiently heavy weapons, you can blow that to bits and watch the kill counter go up by one. Possibly the most badass out of all of these? When escaping from the prison and Alaska, you get a chance to avenge Walker by taking on a battleship and five cruisers, not to mention a couple dozen Nomad escorts. It is near-impossible to destroy the entire fleet, with only a few escorts and the Osiris as backup, with next-to-none shield batteries and nanobots after Alaska, and with a couple dozen Nomads on your tail. If you manage to destroy the fleet, then you are either using hacks, are incredibly lucky, or are the biggest badass space-flight shooters like Freelancer have ever seen.
Once you pass through the Nomad Gate in the final mission, you see the exterior of the Dyson sphere - with a stray planet left outside, simply, I suspect, to give it scale. Then you do a Death Star trench run to bring down the shields so you can fly inside the sphere... which is awesome too, if disorienting.