His performance at the 2012 Grammys. After a performance from David Guetta, Chris Brown and Lil Wayne, he does an awesome remix of "Rope" with Foo Fighters before wrapping it up with "Raise Your Weapon" (which was nominated for Best Dance Recording). The crowd was great, and he debuted an amazing new LCD mau5head.
A minor at the Grammy´s that doubles as a Crowning Moment of Funny: He wore a T-shirt with Skrillex´s actual number on it followed by "u mad?".
His performance at Ultra Musical Festival 2014. Avicii was in the hospital and deadmau5 was his replacement for this year. Consider that deadmau5 has not released an album or even a single since 2012 outside of his At Play series. He essentially showed up out of absolutely nowhere and played a set that was considered to "change EDM forever". What makes this is incredible is he played the most dark and underground set he could possibly design, including many tracks from his new album as well as two minimal/techno pieces. His zero fucks attitude throughout the entire thing not only made it memorable, but summed up Joel's seemingly more cynical and edgy approach as of late. Not to mention he also trolled both Martin Garrix and Avicii within that set.
Two tracks that come in subsequent order: Acedia, and Drop The Poptart/Somewhere Up Here. Both of these were new tracks that were rarely played up to this point. As soon as Somewhere Up Here begins just...holy hell.