Add me to the list of folks who've grown up in the area but have never been to the Watts Towers. I remember watching the television coverage of the riots in the 60s and have always had a negative feeling because of that. It's so time to get over those childhood fears and faulty memories...
Both Winchester House and Hearst Castle are definite must-do's. They both have several kinds of tours you can take. The Winchester one only last an hour or so; the Hearst Castle tour lasts several hours. Plan on buying tickets ahead of time for Hearst Castle as it may sell out beforehand.
Plus one can stay overnight in Cambria, which is right next to San Simeon. The several times I've been there, I've stayed in a quaint motel on the beach and watched the seals play on the rocks, then had a gourmet dinner at one of the many fine restaurants there. Yum.
