I'm going to admit that I'm not the most up to speed when it comes to RPG communities. I got started gaming in my older brother's GURPS games. I then started playing Rifts my freshman year of high school (back in 1996). I didn't start playing AD&D 2E until the summer of 1997 when I purchased the BirthRight campaign setting and then the Introduction to AD&D box set from my local Comics & Comix store.
I went through a 3.x phase in 2000-2003 but I felt into HackMaster 4E for a long time. I didn't really get into other games until I played a game of Castle & Crusades at a local gaming con here in Milwaukee the Nexus Game Fair. I really enjoyed it. I found the rules to be simple while giving me the old AD&D 1E/2E feeling that the original and games like HackMaster gave me. At this time I wasn't aware of the OSR movement at all. I'm still not exactly sure what the OSR movement actually is.
Is OSR gaming just about cloning the original rule sets of D&D? Is it only going to be the Tandy of pen and paper gaming? Do we really want a Tandy 1000 or Tandy 2000 product? On the other hand, sometimes I read about the OSR movement being more of a "feeling" or a "way to play" games which is what got me excited. A lot of modern gaming moved away from the games being focused on player action and then based on the players action the "story" unfolds into the story being told being the prime motivator of the system. I hate that. I like games that allow players to quickly get into the action and not get bogged down so they can be creative with what their characters want to do. But, I also don't want the system to be focused on telling the story. I want the system to be more like the physics of the universe they are playing in and dependent on the players actions but no systems that influence the story directly. An example would be beanies from Savage Worlds or Action Points from D&D 3.5.
Anyway, back to Castle & Crusades. I played in a game at Nexus Milwaukee and had a blast. So, I picked up a few books when TLG had a sale and was happy. I agree with +Erik Tenkar that Castle & Crusades is a Rosetta Stone for AD&D. I love that I can easily run any module or monster with Castle & Crusades with minimal changes. But, when I read forums (such as TheRPGSite) when Castle & Crusades is brought up it seems not to be well liked by the OSR intelligentsia. They seem to prefer systems that attempt to clone pre-1991 rules. But, sometimes, they are okay with the DCC RPG but less okay with C&C.
I guess I am always going to be grateful to Castle & Crusades for getting me back into pen & paper gaming and opening up my eyes to games that I wouldn't have played prior to playing in that one C&C game at a con.