Well, here we have one that I never saw and haven't found! It was aired only once, back in 1989. But you can see some clips and a longer review over at X-entertainment.com. I do see from the credits that they actually credited Alf as "Gordon Shumway," which is a nice touch.
I hope to scare up a copy of this (yeah, yeah, pun not intended) and get a proper review up at some point soon! It's one of the more glaring holes in my collection.