The main character, Kirito, is a wish fulfillment fantasy straight out of a fan fiction, who has no consistency personality, but is consistently idiotic and bad, and the show treats him like the second coming of Christ. His existence is solely to sell merchandise and the show's premise.
The other main character, Asuna, starts off decently, but is slowly turned from a strong, headstrong warrior into a damsel in distress, and is put in the most horrific and disgusting scenes I've ever seen.
And speaking of those scenes (those who've seen the show know what I'm talking about), SAO is downright insulting in the way it handles rape. It uses such a disgusting act as fan-service, which is humiliating to the intelligence of the viewers.
SAO may have some good qualities, but they are outweighed by the stacks of crap it tries to pull off. The only enjoyment someone might get out of this is from hilariously bad it can get; I thoroughly enjoyed tearing every scene bit by bit. Be warned, though; for if you stare into the abyss, remember that the abyss stares at you, too.
