Halloween: H20 was mediocre, but it at least put a nice capper on the series, bringing back Jamie Lee Curtis as Laurie Strode and allowing her to get some closure by killing Michael Myers in a seemingly definitive way (by lopping off his head). It could have sent the series out on a dignified if unspectacular note. But obviously the producers couldn't leave well enough alone, and so they went back to the well four years later, tainting whatever meager legacy they had established with this lame cash-in of a sequel, and totally wasting Curtis in a throwaway opening. Not only is the ending of H20 invalidated with a stupid retcon (Michael actually switched places with a paramedic before he was beheaded), but Laurie is also killed off in a completely anticlimactic way after all she's been through. The first 15 minutes, with Michael tracking down Laurie at a mental institution, have essentially nothing to do with the rest of the movie. Maybe if that part had been fleshed out to feature length, and Laurie had been given a real storyline, Resurrection could have been okay.
Instead, what we get is a pathetic online/reality-TV storyline about six generic college students (apparently there is now a university in Haddonfield) being recruited to spend a night in the old Myers house while broadcasting it all over the Internet. The characters are fitted with cameras that make them look like they're on that old MTV reality show Fear, and director Rick Rosenthal (returning from Halloween II) intersperses the broadcast footage with the traditional narrative of people wandering around the dark and getting killed. Less than a decade later, the whole conceit already seems incredibly dated, and there's no effort made to use it to any sort of clever effect. Instead it's just a flimsy excuse to get these characters in one place so Michael can kill them.
After H20 erased all the convoluted mythology that had been built up in the fourth, fifth and sixth movies, Resurrection goes about trying to create some new, equally useless back story, while reinforcing the idea that those three past sequels are no longer part of the continuity. But unlike H20, this movie has no justification for its narrative; were it not for the opening sequence with Laurie, this could be a completely unrelated film that takes place in either version of the continuity. The storytelling is completely lazy, and the characters have no meaningful connection to Michael or his history. Although Resurrection moves the action back to Haddonfield, there's no sense of the town or how the location plays into the story. It's just a convenient place for Michael to show up.
And instead of the talented young actors of H20, Resurrection offers up Busta Rhymes, Tyra Banks and American Pie's Thomas Ian Nicholas, along with a bunch of other forgettable faces (although future Battlestar Galactica star Katee Sackhoff is amusing as a sassy attention whore). The acting is mostly terrible, and Rhymes brings it to a whole new level of awfulness; the movie's clear low point is when he attempts to use kung fu on Michael. No one seems to be putting in much of an effort, and Resurrection only escapes being the worst movie in the franchise by making at least a modicum of sense from moment to moment, as opposed to The Curse of Michael Myers. The movie ends on an obligatory cliffhanger setting up the possibility of yet another sequel, but that never happened. Five years later, the producers scrapped it all and started over with a remake, beginning the whole cycle again.
Bonus: Here's my review of the 2007 Rob Zombie Halloween remake.