I don't know if I've ever watched a full episode, but I know what Alf is.

Jack O'Neill, however, has never seen it. Why? Because it aired during the same timeslot at MacGyver.

The Wikipedia article on Melmac is interesting. Past the opening line, it's written as if the planet really existed. Now, most articles about stuff in Star Trek, Middle-earth, and so on do this to some extent, but the Melmac article strikes me as different somehow.

Anyway, from that article, it sounds like Alf was a brown Gonzo. The weirdness is very muppetesque. I doubt I'd find it the best show ever, but I'd like to watch a few episodes sometime.