I am blessed in that I have multiple groups that meet regularly, and everyone who I have introduced to D&D has enjoyed it enough to want a more regular game. Overall it makes for about 12 hours a week, with 8 of it being very regular between Wednesday Encounters for four hours at my LGS and a Thursday homegame for 4 hours. The weekend is usually one D&D game from the many monthly groups for about 4 hours and one weekly pathfinder game for another 4 hours. But I won't be counting pathfinder in our D&D survey.
The most unexpected group I have is my parents, who I DMed for twice during Christmas. They liked it enough that I am planning a new adventure for each time I see them. It helps that they both watch Game of Thrones. My mom decided to make her character just like Arya Stark, and my dad who normally has an aversion to fantasy is enjoying playing a mage-hating barbarian who tackles problems with wits and physical might rather than spells.