Final Fantasy 7 Remake
I watch that a couple times every year. That video sums up what an incredible conference that was. It's also why I hope we never switch entirely to some kind of prerecorded video presentation.
I'll also never forget Ubisoft's 2016 trainwreck. It was so bad that I enjoyed watching it.
Still, nothing beats Microsoft 2011. I laughed so much. It was an incredible display of comedic timing and creativity. Brilliant, absolutely brilliant.