In this case, I'm differentiating between regular sequels and legacy sequels, which arrive several years, often decades, later. Hence Jaws, Transformers, Die Hard, Fast & Furious et al don't qualify. Perhaps I should have made that definition more clear.

However, I one hundred percent agree that I could happily live without any of the Jaws sequels, etc. :) I've written about rubbish sequels here, if you're interested. At some point I'll write a piece on good sequels (which will include Aliens, as you mention). :)