Erika Eleniak
I never watched this show as a kid, and I've still never seen a full episode, but I did catch a few clips of the show, once they were available online (i.e. YouTube), and after I became aware of Erika Eleniak in films like Under Siege, The Beverly Hillbillies and the underrated A Pyromaniac's Love Story (although I didn't realise, until sometime later, that she was the 'Pretty Girl' in E.T.)
Anyway, she's stunningly beautiful, and although she may have posed for Playboy on a few occasions (a magazine I abhor), she has a much more wholesome and sweet vibe than some of the other women who emerged as stars from this show. I also see that she was on the show *before* it became a T&A fest, and back when it still had a pretence at being a proper, if lightweight, drama series *with* a few hot women, rather than a show centred around scantily-clad hot women, with next-to-no drama.
Plus, she actually had a genuine character, and wasn't *simply* there to look beautiful (she's no Oscar-nominee, but Erika is clearly a better actress than pretty much all the women who appeared on the show, and arguably most, if not all, of the men, the Hoff included). Her pouty spoiled rich girl, who learns humility and comes-down-to-earth, may not be the most complex character in the world, but it's still far more compelling than a simple mannequin with zero backstory and zero personality.
Anyway, suffice to say, she was IMHO the most beautiful woman on the show, arguably the best actor, of the regulars, and arguably the most compelling female character.