The current long running game (39 sessions now) started with Lost Mine of Phandelver, and I have thrown in a lot of side quests based on their backgrounds and several extra dungeons in the mix. However, two sessions ago, they officially started on the Horde of the Dragon Queen where I replaced the small town of Greenest with Leilon and really beefed up the bad guys. PCs were too late to stop the attack in anyway, but could track them. They are now in the Roadhouse, getting close to level 10.
Two other games I have run have been for my 12 year old son and two of his friends, just using Horde of the Dragon Queen (cause they like dragons). This is technically still on going.
Also ran my two kids and wife through some old Thunder Rift modules. Lots of fun, but not technically ongoing any more.