The end of the Dragonfall campaign. Finally ending it all after days of sweat, blood, and tears.
Eiger ripping out the throat of a man who caught her while reloading. With her tusks!
The whole crew kicks all sorts of ass during the attack on the Kreuzbasar. They've been caught flat-footed and they're all divided across town, separated between large groups of heavily-armed mercenaries. They still manage to band together, kill every hostile down to the last man, and defuse all the bombs set to blow up in the sewers. It's a rare moment of genuine heroism from the shadowrunners where they save hundreds of innocent lives, and you get to control all of the original crew at the same time (including Dante, who just Took a Level in Badass).
One mission has you storming the research center of one of the major corporations, killing their researchers, freeing some prisoners, and setting the entire building to explode. It's a hard as hell mission that required a lot of prep work but you will be on top of the world when that building goes up in smoke. The fat paycheck that comes with it is a nice touch too. Double points if you manage to get to the lab without tripping the alarm.
The cherry on top was that this was a morally good act (said corporation is Aztechnology, known for their Black Magic and an attitude most other megacorps are repulsed by; the place you blew up was researching ways to clone a Human Sacrifice), and in the life of a Shadowrunner, that comfort is a VERY rare luxury. Taking the more moral road can result in a Shadowrunner's reputation suffering and angering clients. To be paid to do the right thing just feels wonderful.
Meta example. Harebrained Schemes put up a Kickstarter for the Hong Kong campaign, in order to add more to it. They asked for 100,000 dollars, with 35 days for it to be raised. It was raised within two hours. Two weeks later? 700,000 dollars and they still had three weeks to go. Their last stretch goal? 1 million dollars for an additional 4-5 hour epilogue campaign, which they also made.
In Hong Kong, one way to defeat the Big Bad is to outwit it by using its own rules against it. Specifically, you force Qian Ya to retreat to its home dimension by threatening to use the machine that summoned her to summon all of its siblings. When she/it incredulously asks you what makes you think you'll survive an encounter with the other Yama Kings when even one is beyond your ability to kill, you can reply that you won't, but that won't stop the others from killing her for stealing all their food. Defeated, Qian Ya tries to bargain with you by taking the souls of her followers with her, but as Yama King law states that any concession in an argument forfeits all rights, you can order the god-queen home empty-handed. Even better is responding to her asking how you know the Yama Kings' laws, and you can either tell her... or tell her that, "You'll spend the rest of eternity wondering."
Helping Ku Feng to unleash her true potential will unlock her for the final battle in Kowloon Walled City.
Taking A Third Option in the Whistleblower run in Hong Kong. Rather than side with either your original Mr. Johnson (who lied to you and is planning to betray you) or the Seoulpa Rings (who threaten you and are planning to betray you) you can decide to fight both sides in a glorious three-way fight. This not only gets you the greatest possible reward for the run, it also gets your character a lot of respect from both their teammates and Kindly Cheng, who strongly approves of the "nobody fucks with Cheng's runners" message you have just sent.
At the end of the Prosperity run, you have to face one last group of mooks, whose captain says that they're the last line of defense. You can then have your character point out that they're the last line of defense because you killed the other lines. They wisely back down.