The extended cut is an Alan Smithee film. They seriously screwed up some FX shots that was his real bone of contention with the EE.
There is a miniseries produced by the SciFi channel that is slavishly faithful to the book. Mostly set against CGI, this isn't as well acted, but is certainly a good watch at least once. But the Lynch/Smithee film merit rewatching like any great cult sci-fi piece.
The recent attention I've given the film reminded me how damn good it really is. Weird, but good. Brilliantly acted by everybody (except maybe Alicia Witt) and directed within an inch of its life. Not to toot my own horn, but if you're going to bother, pick up Fan Filtration's version or my own, as they both correct the worst of the EE flaws. (I haven't seen FF's version yet, but I'm pretty confident in his edit from what I've read.) If the film was worth it to not one but two of us to re-work, that is a testament unto itself.