In many people's minds, Dungeons and Dragons was largely responsible for the greater popularization of roleplaying.
It has a long history in the limelight to be sure, but a great many gamers have mixed feelings or outright hostility to the rampant commercialization and lack of dedication to the spirit of roleplaying which much of the D&D franchise has shown.
- aka D&D
Alignment was something first brought to public light through D&D. It was a well-meaning idea, but in practice it is at best generally useless to creative gamers and at worst a terrible and fun-damaging hurdle. See Playing in character, and the problem of alignment.