Source: wallpaperup.com
6. Annihilation
(Annihilation #1-6; Annihilation Prologue #1; Annihilation: Nova #1-4; Annihilation: Silver Surfer #1-4; Annihilation: Ronan the Accuser #1-4, Annihilation: Super Skrull #1-4; Drax the Destroyer #1-6)
Admittedly, a lot of this list is composed of 80s books, because those seem to have fallen far enough into the forgotten crevices of memory for them to be considered hidden gems. Annihilation is fairly recent, and a lot of people have read it. However, that will become less true the farther we get into the future because THE DAMN THING IS STILL OUT OF PRINT.
What the hell, Marvel? Fix that!
And it's not like it's an easy one to track down on your own. It's composed of four official tie-in miniseries, one event miniseries, and one prelude miniseries, plus a prologue one-shot and some assorted bonus books. And there's no way outside of the internet to track down what order the whole thing is supposed to be in.
Jesus, Marvel, just let people read about Annihilus leading his monsters through the cosmos, only to be stopped by Nova, Super Skrull, Ronan, Silver Surfer, Drax, Gamora, and Star-Lord. This isn't complicated.
