I was lucky enough to get hooked on Roberta Williams' work at KQ2 -- it was really the addition of the SQ easter egg that did it for me, as there are some "cheats" in KQ2 game design where if you didn't do things in just the right order, you couldn't finish the game and might not realize that for quite some time. I think it took me about a month of playing and frustration (and discovering ALL the game mechanics in the first section of the game) to realize I'd done two actions out of order, and that's why the game wasn't progressing.
I thought the KQ and SQ series were great; for me, LSL and PQ cheapened things a bit. I liked Roberta's storytelling more than Sierra's game engines.
I'm very happy that Sierra took over Broderbund's Lode Runner franchise though -- Lode Runner Online is a game I got back then because of the combination of Lode Runner and the Sierra label, and my kids still play it today!
for those reading the thread who have no idea what we're talking about:
http://www.postudios.com/company/games/thesilverlining/
It's 5 episodes long, all available for free. I'm thinking of getting a WineSkin bundle set up and sending it to them so they've got a legit Mac download available :)