2. Star Wars: The Original Trilogy
Considering how lambasted and lampooned George Lucas is for his more recent work - and especially the Prequel Trilogy - his work in creating the Star Wars property can never be over-emphasised. The films have inspired the kind of longevity in a franchise that defies the restrictions of media that all creators must wish for, and they have long-since moved into the area marked cultural phenomenon. And though the films individually are far from flawless, as a Saga, the original trilogy is still exceptional, and hugely complex in terms of both the storylines we see, and the mythologies and alternate timelines that are established around the main plots (which have of course inspired a huge, vibrant wider universe.) Lucas's great success - like that of JK Rowling - is in creating a fictional world that fans feel part of: it isn't just a matter of vicariously living through characters, or escaping into that world, it is rather the authentic feeling that the rich tapestry painted around the films actually exists. That is the triumph of great story-telling, and while the Prequel Trilogy failed on a large number of issues, the Original Trilogy still deserves to be counted as one of the finest trilogies ever made, and certainly the finest sci-fi series.
The Uncharacteristic Low Point? The re-edits that neither George Lucas, nor anyone else had any business, nor any actual need, to add when the films were re-released (aside from the digitisation of Jabba The Hutt, which was inspired.) Also, Ewoks.