Return of the Jedi HISHE
Briefing Room Scene
During the briefing room scene, as the Rebel soldiers are speculating that the Empire just let the shuttle be stolen, one goes so far as to suggest that it was a trap. Ackabar then interrupts, saying that it's not a trap (a parody of his famous line; "It's a trap!").
During the party in the ewok village, a single Mon Calamari officer is seen dancing in the background. It is unknown wether or not this is Ackabar.
Guardians of the Galaxy HISHE
Admiral Ackabr makes a cameo in How Guardians of the Galaxy Should Have Ended, in a display case behind the collector.
Man of Steel HISHE
As Superman arrives with the capsule, General Zod realizes he had no way of knowing the codex is what he wanted. Just as Superman throws it at the Ship, Admiral Ackabar, dressed in a Kryptonian Millitary uniform, appears and shouts "It's a trap!" (Another nod to his line).