Honorable Mention 2: Re-Re-Reboot
Marvel has never had an outright, ground-up, end-to-end reboot. DC has had three hard reboots and a couple of soft ones.
The first DC reboot was the start of the Silver Age of comics, when DC replaced Jay Garrick and Alan Scott with Barry Allen and Hal Jordan and renovated from the ground up. Round Two was the maxi-series Crisis on Infinite Earths, which blended DC’s multiple alternate earths into one unified timeline, folding characters like The Justice Society, Captain Marvel, and The Question into the same continuity as everybody else.
This created the legacy-happy DCU we all know and love. Then 2011 brought us the New 52 reboot, which was pretty much another start from scratch. And currently, the DC Rebirth event is soft rebooting a lot of elements of the universe, with Superman as the most recent. On the other hand, Marvel has never hard rebooted, although they went through a really soft reboot after Secret Wars (the 2015 one).
A couple of dudes got folded into the continuity (mostly Miles Morales and Old Man Logan), and some small stuff was changed, but everything else pretty much picked up where it left off.
