D&D 4th Edition is coming out. I had no idea D&D still existed. [edit: More accurately, I knew people still played it, but for me, D&D is still represented by the AD&D Dungeon Master's Guide circa 1979. The idea that the game would have evolved after I last played it in 1984 never occurred to me.]
When I was in college, Dungeons and Dragons (AKA D&D) and Traveller (a similar game set in outer space) were really fun, creative outlets for us. The man who ran our D&D world and the one who ran the Traveller universe were incredibly creative. They created experiences that were akin to participating in creating a series of stories with a bunch of good friends.
Because I was in school with a bunch of people who knew science better than the average person, our D&D world and Traveller universe had rules that were different from the official versions. Our spaceships accelerated, decelerated, and maneuvered in ways that were at least somewhat consistent with the laws of physics. People took damage (had injuries) in ways that made biological sense. Technology progressed over time so that if you had technology that could help you hide from or find your enemies, it wouldn't be effective forever. In our Traveller universe, there was a rich technological and political environment.
Any time I hear about D&D, I think about "Flow" (Kevin Oliveau who ran the Traveller Universe and then founded a cohousing community) and "Noqui" (the late, great Karl Horita who ran the D&D world.) I haven't played anything like D&D or Traveller for 24 years, but I still have fond memories of the stories they let me participate in.