4e Ashes of Athas - played everything but the finale module, most of it in "first run". Between convention slots, offered a thick sheaf of paper to an Ashes organizer and saw some of my ideas in the later modules - most cool. Convention releases took about 3 years.
HotDQ / Rise of Tiamat - began playing HotDQ at Balders Gate, continued to the flying castle. Was asked by the group to become DM (previous DM graduated college and returned home), aboard the castle. Finished HotDQ and continued Tiamat through the green dragon lair. Had to drop out (and group broke up) due to job interference. Not quite 1 year total.
My new group has played chunks of Yawning Portal, completed Dragon Heist, tried to do Undermountain but the DM's job cut him short, ran a series of Tiamat season AL modules and began the Slaver series, and recently started Saltmarsh with a second DM.