Probably my absolute favorite role play world.
I'm all about the Third Edition though, haven't cracked fourth, and am a bit frightened of Fifth.
I got into it really bad just before the turn of the 2000s. Got nearly all the main sourcebooks for each class, as well as a couple equipment books. (I have a "Box of Shadowrun" in the basement.) Read all of them cover to cover, something I haven't even done with D&D. I even got so bad as to create my own custom stuff... before I even played one game. Like, realistic car models and such. It was... an obsession, really.
My favorite and longest lasting character has to be Rook (aka Raven, aka "R") my Decker. During his five years of gameplay, I amassed over 100 Karma points, and was a pretty badass decker. One Hacking roll I made took 52 dice, and had (with "opening up" the dice) on the order of 40 successes.
the GM was all, "Okay, you own this node. What do you want to do?"
During one of my final appearances with that crew (I joined the military shortly thereafter), my character ended up sacrificing himself to save the team. An awesome way to go out for an awesome character.
Any other Shadowrun aficionados?