15 Video Game Sequels That Totally Defined Their Franchises

6. Mass Effect 2

Let's hop over the life-scarring end of 3 - as that did define Mass Effect too, but not in a good way - and instead focus on when there was no experience on this earth better than a good romp around the galaxy with an assortment of different-coloured aliens. ME2 basically took everything that worked from the first game - the conversation tree, sense of immersion in a fantastically-realised galaxy, a string of lovable characters etc. - and threw in one of the best driving narratives in the business. Straight away Bioware shook everything up and defied every expectation by killing off hero Commander Shepard, before throwing him (and you) into a galaxy-wide war between the mysterious Collectors, all backed by the mysterious Cerberus from the first game. Where your allegiances lay as you amassed a suitable Avengers-style force to fell this villainous force became the source of some of the best decisions and moments in the whole trilogy, and as the whole thing drew to a close and the aptly-named Suicide Mission took its toll on your squad, it cemented the entire experience as one of the best in all of video games.