Pioneering in its attempt to make television entertainment that mattered and feature fully formed characters with real motivations. It hit all of the hot buttons of the era, besides issues of inter-generational conflict and race relations it dealt with pretty much every other social-political question of the period. Unfortunately, the fact that it was so current in its day has meant that it doesn't stand up as well as the slapstick comedies that preceeded it, except as a period curiosity, 35 years later. Like a lot of programs of its era, it ran until the wheels fell off and the last couple of seasons don't serve the series' legacy well.
