We actually own all the King's Quest games, and pretty much every major adventure game made during the '80s and '90s, though quite a few of them are on hard or floppy disc so are essentially useless. Does ScummVM play Sierra games as well? I never bothered checking.
Apparently Activision released the King's Quest and Space Quest collections on Steam but for some inexplicable reason they are unobtainable in Australia. This is annoying because I wouldn't mind having them tied to my account. I may just pick them up on GoG.
Edit: Looks like you guys were busy talking about ScummVM while I was posting anyway. And in the process answered my question.
"Now, if you'll excuse me, I have some massive internal hemorrhaging to attended to."