Tabletop RPGs have made and continue to make a big difference in my life, as this article expresses well. Not only D&D, but Call of Cthulhu, Champions, Gamma World, Star Frontiers, Top Secret, Paranoia, MechWarrior, Vampire the Masquerade, and many more. Just listing them evokes a constellation of emotions and memories within me of time spent with friends over the years. I've never been happier than when creating a collective world around a table for an evening... or an entire weekend!
The article is short but sweet, structured around how D&D mitigates Jane McGonigal's 5 dying regrets.
A Life Playing D&D: http://www.critical-hits.com/blog/2014/02/25/a-life-playing-dd/