-This review accounts for both Sword Art Online I and for Sword Art Online II. There may be some spoilers ahead.-
This was one of the first anime I've watched, and it's also the anime that got me into anime. I feel like some people leave negative reviews for almost no reason, since the story isn't half bad and the art while fighting is some of the best. This does not mean, however, that the anime is perfect, because it's far from that.
First of all, some of the fights during the anime felt rigged. Almost like someone was cheating. For example, during the final fight with
Kirito and Kayaba, Kirito's eyes went yellow for some reason and beat Kayaba in an instant. I also had a problem with them fighting before.
Second of all, I dislike how Kazuto Kirigaya was the protagonist for both season one and two. He shouldn't of made it past the first half of season one. This would have made the anime feel newer when each season came out, but instead, we have to watch the same overpowered Kirito save the day once again. If Suguha Kirigaya(Kazuto's "sister") was the main character for the second half, it would have made me like this anime even more. This also accounts for season two especially, since Sinon could have been the leading character there.
Third of all, I feel like the second half of the second season is dead. They use the exact same characters with no new features and just feels like a rip off of season one.
The anime isn't bad though, and if you actually gave it a chance, I think you'd enjoy it.