The gameplay mechanics are such that Rico can star in one every thirty seconds or so.
The ending of the first game deserves special mention. After Rico jumps out of his own plane and onto the presidential jet, climbs inside, and massacres the dozen or so heavily armed bodyguards protecting Salvador Mendoza, the San Esperito dictator, his target bails out of the plane at ten thousand feet in an act of desperation. Rico leaps after him, controls his fall so that he is right above Mendoza, and plants a stick of dynamite square in the middle of his back. He then opens his chute and glides away, muttering "See what happens when you piss me off?" as Mendoza explodes in a massive midair fireball behind him.
Just Cause 2
The second game's ending is even more intense than the first. Baby Panay, Panau's dictator, has nuclear missiles aimed at the U.S., Japan, Russia, and China, as they're fighting for Panau's rich oil supply. He launches them, but gets caught on one of the missiles. Rico grapples onto another one, and as he gunfights Panay while surfing the nuclear missiles, he disarms the missiles one by one. At the last missile, the one Panay's riding, he jams Panay into the missile and redirects its guidance system to explode above Panau's oil fields, thus ensuring that the four countries will stop fighting for Panau.
Even though they're the enemy, credit has to be given to the Panauan soldiers. Imagine it: your base camp, quiet hours before, has turned into a raging firefight. Your shotgun clicks empty, and you hunch behind the wall corner He's come, that American devil the men whisper about at night. They say he's stolen helicopters, tanks, jets... anything he can get his hands on. He once dragged a man two miles behind his car for no reason. He has some kind of hook, and he flies around with it like some kind of mad bird. He's killed hundreds, if not thousands, of grunts like you, and he's here, now, hunting you. The base is in ruins- broadcast towers down, the SAM sites smoking craters. So what do you do? You reload.
Although most of the side missions are generic "kill all these guys", "blow up these vehicles/buildings", "escort these guys", etc., there are quite a few legitimately awesome set pieces as well: these include Fry Me To The Moon ( where you blow up several rockets to sabotage Panau's spy satellite program, and have to jump into a jet to shoot down a fourth in midflight), Pirate Broadcast( where, after scaling up the Panau Broadcasting Station, you have a rooftop firefight with several goons to realign several transmitters to broadcast a message for the Reapers. After that, you set charges to the big transmitter, and jump off the roof while it blows up behind you), and Stranded ( where, after flying to an island an Ullar Boy drug transport was lost, your plane is blown out of the sky by an EMP, and you have to work with the Sole Survivor to dismantle the EMP, as well as fend off the Japanese soldiers stationed there since World War 2 (well, either them, or as WMG puts it, regular Japanese soldiers disguising as them to scare locals off the island), culminating in a mad dash in the cargo truck with the phantom IJA army chasing after you.)
A list of some of them by mission start like this.
Your first mission is to grab a dead body which has fallen out of an airplane with vital intelligence on a PDA, then break into a military base to recover the other PDAS by singlehandedly destroying the entire base.
The next part of the game has you scale the side of a casino to dismantle a series of bombs and rescue an informant from the Panau military—all without ever using an elevator.
Virtually every Stronghold assault has Rico using a gatling gun to wipe out a helicopter by himself then go to town on the base afterward.
The very premise of the game's side-missions is badass. You have three mutually exclusive Resistance groups. You play them all against one another to get the intelligence you need.