I didn't have this category last year, but there were a lot of miniseries this year, in no small part due to Marvel's Secret Wars event.
In fact, more than half of the series on this list came from Marvel's Secret Wars event, even though I wound up souring on the main event before the end. The rest are all Marvel too, with the notable exception of We Stand on Guard, another great Brian K. Vaughan book with fantastic art by Steve Skroce.
1. Civil War #1-5
2. Spider-Island #1-5
3. We Stand on Guard #1-6
4. Shield (The Cavalry, Mockingbird, Quake, Agent Carter)
5. Runaways #1-4
6. Thors #1-4
7. 1872 #1-4
8. Amazing Spider-Man Renew Your Vows #1-5
9. Star Wars Journey to Force Awakens #1-4
10. Avengers: Ultron Forever (Avengers #1, New Avengers #1, Uncanny Avengers #1)
Just missing the cut are five more Secret Wars tie-ins (Planet Hulk, Captain Britain & Mighty Defenders, Infinity Gauntlet, Future Imperfect and Squadron Sinister), Princess Leia, Star Trek Green Lantern and two Image books, Airboy and Chrononauts.