Okay, so it's actually not bad. Especially given the fact that it is a set of History/A&E shows from the 90s, and the CGI was still finding its feet. Cheesy graphics aside, this was a moderately interesting set (well worth the $4 at Costco I shelled out). If nothing else, it's worth remembering that there are large numbers of people out there who believe in aliens, despite never having seen one and there being exactly no evidence of any kind (physical or otherwise) that stands up to anyone's reasonable definition of evidence.
The most interesting episode was IM-not-so-HO the one on UFO Cults. The Heaven's Gate Cult had just done its thing, and they spent a good deal of time going over that. They even managed to interview both a member of the Cult (NOT a former member- he didn't kill himself, but only because the police managed to stop him in time) and this guy, who I don't know much about but who has filled the shoes of Walter Martin, for whom I do have a healthy dose of respect.
All in all, worthwhile if you've got any interest in fringe movements. Otherwise, I'm sure there's better stuff available on aliens (though I couldn't tell you what).