Nah man, you gotta have the full leak spectrum. We can't ignore the Palutena leak, ESRB, Shovel Knight, and my forever favorite "leak": Rayman.
Those leaks/rumors may have been just as relevant, but for me, the one that i always remember, is the Gematsu Leak, mostly because that one lasted for a big amount of time (it started a before E3 2013 and ended on July 14 of 2014).
Sure the Rayman rumor is something that a lot of people remember, but that lasted only a day (or a night,). Althoguh i must say, that was the only Valentines Day that i ever enjoyed (all thanks to Artsy Omni).
The Palutena images kinda overlapped with the Gematsu rumor in a way, so i sort of count them as well (even though those images were completely unrelated to the Gematsu Leak).
I never believed on the Shovel Knight Leak, not even once.
But the ESRB leak...........