SAO is my favorite anime. I don't know why, but apparantly on reddit this is an incredibly unpopular opinion.
Kirito is an interesting and multifaceted character that I can personally connect with, the art and music are gorgeous, the story and plot are compelling, and the overall presentation is above almost every other anime I've watched.
I have watched Clannad, Steins;Gate, Madoka, Cowboy Bebop, Monogatari seasons 1 and 2, Evangelion, and full metal alchemist, and none of them were even remotely as good as SAO. It was so good that I re-watched it twice right after I watched it originally, then I watched it again when the english dub came out. It would be fair to say that I believe it is the best anime made so far.