This show has an amazing premise, but is ruined by a writer who does not know what he is doing. The third season is a trainwreck or epic proportions that has too many characters, is too long, has terrible villains, and tries to make you care about every single character you see. I may not even see how this arc wraps up due to how awful season 3 is.
My rating for each arc
Aincrad Arc: 5/10
Fairy Dance: 2/10
GGO: 3/10
Filler Arc: 2/10
Mother's Rosario: 4/10
Alicization: 1/10
It is such a shame that a premise as awesome as Sword Art Online's is wasted by a writer who probably took writing lessons from George Lucas.