Just some thoughts on some rides others have mentioned:

Mt. Hamilton Challenge is a super fun ride. The way they bring your own food up for the rest stops is a pretty cool system.

Holstein 100 is EXCELLENT. The food is great and it's staffed by all these super sweet senior citizens because it supports West Marin Senior Services. And it's roads we ride on all the time, so that's fun.

Mel - what's "Tour di Stupid"? Sounds like something I'd do....