I discovered the series as a blind buy on DVD about six months ago. Yes, the alien biology was pretty implausible, but the ideas behind the series were very adult and very thoughtful--something you don't get from the usual science fiction series. I thought Green Eyes was a great finale, although I agree that every character does seem to end up in a pickle at the same time.
I picked up the Movie box set as well as the original movie after finishing the series. I didn't overly care for Dark Horizons because of all the ret-cons to the series regular, and Sykes' hair looked awful (that seems incredibly superficial, but it really bugged me). Luckily, the second film, Body and Soul, was better. I look forward to the rest of them (haven't had a chance to watch since starting this semester, but that will all be over next week).
As for the original film, I watched it a couple of months ago, and with the exception of a few things, found it to be pretty awful. I realize now its where all the implausible trappings in the television series come from (I'm pretty sure salt water is acid to the aliens solely for an easy out to the ridiculous finale). Worse, it doesn't have any of the series' ideas. George's family is barely seen, and Newcomer culture is pretty one-dimensional.