I suppose that you mean SAO.
SAO isn't that great of an anime, they kind of lacked on character development, but I love SAO.
Why?
Well, I simply get attached to characters quickly, and here we have Kirito and Asuna, I instantly fell in love with them, and they're probably my favourite anime couple next to Tomoya and Nagisa.
Adding Yui to the bunch just made it much cooler, and to be honest, I felt that skipping anyone else' development and adding the part where they were together in a house in the woods, was awesome.
The artwork and soundtrack are also really good, can't hate that.
The novel isn't that bad, they kind of made Asuna a bit useless, only 1 novel after GGO that she actually was a good/strong person like in the SAO arc.
For the rest some really saddening things happen for about 6 volumes, I won't say what happened but it was pretty heartbreaking for me.
Either way Asuna went from hero to zero but I still love the couple, especially with Yui.