Fuck I have so many of these stories:
One of my favorites was a continued session in our Shadowrun game. My friend John was GMing for myself, my friend Phil and their cousin Tommy; Phil and I were playing some pretty standard characters. And Tommy was that one guy who always takes as many of the flaws as he can to get the biggest jump on characters stats that he can right out the door. One of these flaws was an extreme sense of paranoia with no trigger on his wireless reflexes. In this case we are talking about an Ork with the street name of Nemesis, a psychotic street samurai with the people skills of a wood chipper.
Anyway. Having grown tired of Nemesis over a few sessions of half-botched runs due to him being quite dumb, Phil and I spend some of the session convincing him that Ares is going to send their elite assassins after us...and they often disguise themselves as grandmothers or old people because that is so unexpected.
So after dicking around for awhile in which Nemesis goes out of his way to buy a few new guns and a big knife, we go down to meet with Mr. Johnson at a steakhouse in the Renraku Arcology where Nemesis proceeds to try to subtlety threaten Mr. J into giving us more money but cutting his cuticles with his new very large knife.
Further annoyed after a nearly botched negotiation and job interview, and ready to see this character gone, I decide to see if we can get Nemesis killed. So we walk out of the steakhouse I say my character wants to hit up a small shop to check out some of the new legal decking gear that is available and I purposefully begin to scan the crowd. It is at this time, with a glance to our GM, that I mention to Preacher, the other runner, that there is an old woman with a young man walking behind us. So we start acting more alert and ready like this might be an attack incoming. And then Preacher quietly tells Nemesis about the old woman and her companion.
It is at this point Tommy as Nemesis utters "Oh yeah? We'll see about that." and he proceeds to pull out his ork sized Ares Predator and shoots the young kid for his surprise action. Having wired reflexes he is naturally faster than grandma whom he picks up and repeatedly swings like a rag doll into a security window to see which one breaks first.
Naturally this creates a lot of shock and awe with people screaming and running for their lives because some large ass ork is rampaging and murdering people. In the end, Nemesis was gunned down by about 15 Renraku SecGuards in a pitiless attempt to go out in a blaze of glory once he got surrounded, with neither of us getting a second look as we bailed as soon as there was enough panicked people to blend in and get away.
Another Shadowrun game, same people, same GM. Reprising my own character and Phil on Preacher, Tommy has decided to make Toughness...a Troll Mercenary with a take no prisoners attitude who would threaten everyone he disliked with anal fist disemboweling.
The job was supposed to be very simple. Sneak into a small Fuchi subsidiary and steal some paydata and a prototype. Since Toughness was a huge hulking troll that walked around in light security armor, we decided that his job was to sit in in his armored van outside and provide us with overwatch and if necessary a distraction - if we set off an alarm.
The infiltration was easy enough and while we got into a few mild scuffles inside the job was relatively silent and body count free. We had just gotten into the labs and I was getting the data while Preacher recovered the prototype. Things were smooth. It was at this time that the GM informed Toughness that a large UPS truck had arrived out in front of the subsidiary building blocking his view.
Instead of doing something reasonable, like moving the van to a different spot. Toughness instead gets out of his van and gets out the belt-fed Panther Rotary-Assault Cannon, that only the GM knew he had, from the hidden compartment. It is at this time he proceeds to shell the UPS truck. The front of the building. And any pedestrians unlucky enough to be on the sidewalks.
He spent 5 rounds burst fire shelling the landscape and then he got in his van and drove off. Naturally, Preacher and my character barely escaped with the goods. So to lay low Toughness retreated to his low lifestyle hideaway thinking he could go unseen until the matter blew over and he could get his cut. He did not count on us selling him out to Lonestar for a hefty bounty. Toughness died to a mage dumping a world of hurt into him from astral space.