Probably the best moment was when all 3 of them were standing out in space starting at the space ships waving and it cuts to kirito and a "ghost" of eugeo.
I think that the Alicization arc was by far the best one next to Aincrad arc having this new cast of characters really gave them time to flesh them out and make characters that really mean something.
Im hoping that we get SAO Progressive within the next few years and im really hopeful that its going to be amazing. with them finally returning to Aincrad im hopeful that they really flesh out Asuna and Kirito during there early levels, and show a lot of the floor bosses that they skipped in the original season. I am very hopeful just kinda sad that there wont be another season for a few more years.