I'd say Street Fighter II is the greatest sequel ever. It was the sequel to an utterly forgettable game and happened to create the modern fighting game. The reason I think it stands above all else is because it had no true foundation to stand on. It was a sequel that had to truly reinvent itself into something much greater. Considering an entire genre is based on the innovations in this sequel alone, I'd say there's no real contest here.
There are other great sequels, but I don't think there is any other sequel that had passed it's predecessor so far to truly make it completely forgettable and unimportant to the genre it's in. Every other sequel here was based on a game that was already good or great. It was a mere add-on of features to an already solid formula. Street Fighter II made people forget Street Fighter even existed. Even now, there is a large majority of fighting game fans that have never played Street Fighter. There just isn't a point.
Tag: Became a freaking mod and a complete douche, coincidentally, at the same time.
