I have a couple I'd like to throw into the ring.
1. Ex Red Samurai (Ryuu). As is the case with most Red Samurai teams, he trained and graduated camp with his team. They were one of the most efficient and savage security teams for Renraku locally. Unfortunately, jealousy tends to target such groups. His team was framed as betraying Renraku by a fellow Red Samurai team. While on a mission, his team was ambushed by Renraku forces. He narrowly escaped with only some gear and his katana. Having been left for dead, Ryuu escaped to the only place he knew where someone with his military background and training could hope to make a living, the shadows. He now uses his skills to survive long enough to find the team that betrayed him and avenge his former team. Having tempered his skills on some of the most vicious missions for Renraku, there aren't many jobs that he won't take.
2. Bad luck can hit us all, and the rich and powerful are no exception. Johnny "Shakespeare" Roberts was raised for the stage. His parents were local stage performers, his father specializing in method acting and his mother in performance makeup. They were a picturesque family who new very little of the hardships that the city has to offer. That was, until their theater troupe went bankrupt. You see, with the proliferation of BTL and Trivid entertainment, fewer and fewer people were attending their stage performances. Further, plays like The Tempest lack their intrigue with figures more grotesque and alien than Caliban running around in the sixth world. Having to abandon their suburb life for the sprawls, Johnny's parents were ill equipped for the dangers of the sprawl. Those dangers ended up getting the best of them when they were caught in a firefight while leaving their apartment. On his own, Johnny proceeded to take one dead end job after another, eventually ending up working at a local Stuffer Shack. One night, the stuffer shack was held up at gun point. Johnny talked the robber down, exhibiting professional control over his communication. In a turn of luck, one of the patrons of the shack was a man who went only by Johnson. He was impressed with Johnny's ability to remain calm under pressure and stated that his talents were wasted in such a lowly position. If Johnny ever wanted to make some major creds, he should give him a call. Since, Johnny has served as negotiator for multiple deals with Mr. Johnson. Whenever there's a job that requires masterful control of one's body, Mr. Johnson knows he has an ace in the hole.
3. On the surface, Teddy Freeman appears to be a successful stock broker. He lives in a luxury rooftop apartment in one of the most expensive complexes in Downtown. His maids and security forces may be a bit puzzled by some of the guests that he has over, but for the creds they're getting to do their jobs, they're not about to question anything. In reality, Teddy Freeman is "Rags". A dealer known throughout the sprawl as the go to for any addict's needs. BTL, novacoke, zen, deepweed, escorts, the list goes on. He has the connections to get you what you want and the silver tongue to make sure that you're paying a premium. Now, don't let this all fool you. While he's protected in his fortress, he's no stranger to the streets. Rags grew up on them, and didn't get this high up on the ladder by not getting his hands dirty. When there's a collection to be made or a new cowboy setting up shop in his territory, Rags prefers to personally handle his business. Addiction, however, is like any market. There's ups and downs and Rags has grown accustom to his lifestyle. When the going gets tough and he needs a few more creds to keep up the security detail in his apartment, he's not above taking to the shadows to make that extra bread. Not like a client is going to turn down someone who not only has the skills to get the job done, but the connections to make sure that you're satisfaction is always guaranteed.
4. Tank didn't know what his real name was. He was raised in the Barrens, but could not tell you how he ended up there. He did stand out a bit, but that will happen when you're a Troll. It's a bit hard not to stand out like a sore thumb. Tank was found in an alley one night, while some gangers were heading home from a local dive bar. They heard some rustling around behind some garbage and decided that they felt like unloading some stress. They fired half a clip each into the garbage to see what was causing all the ruckus. To their surprise, they found a little Troll. Though, little is subjective. What they found was Tank at age 3, standing at around three feet tall. He was covered in filth and had been rummaging through garbage looking for food. To their surprise, he seemed barely phased by their assault and looked at them with blank naive eyes. One of the gangers had a flash of brilliance and decided to take the Troll under his wing. This proved a boon for the gangers. Tank seemed nearly immune to mystical assault. This coupled with his natural resiliency to physical damage earned him his name and reputation among the street urchins. His near indestructible exterior mixed with his limited cognitive abilities provided the amateur criminals with quite an edge over the competition. All they had to do was point him in the right direction and let him utilize his natural talents for destruction. Tank was happy to just be fed regularly and felt like a part of a family. Through the years, Tank was forged into a formidable machine of destruction. Sure, he was better at taking order than giving them and sometimes found himself getting a little carried away in the heat of a battle, but that type of brutality has a place in the streets. Besides, it helps when you tower over your opponents and can brush off a stunbolt to the face. Whether ripping apart enemies with his bare hands, cutting through the very fabrics of the astral plane to pummel a spirit, or unloading a clip of machine gun rounds into a rival gang's hideout, Tank loves and lives for the carnage.
There's my ideas. Let me know and I can send character sheets for more detail.