If you're in the east bay, there are a number of options that I used to love... my favorites:

From Castro Valley to Milpitas, through Palomares, Niles Canyon, and Calaveras: google maps link
Careful on Calaveras as much of it is one lane.

Then from CV to Moraga via Redwood Road gmaps

I grew up in CV and spent most of my free time my junior and senior years in HS driving those roads.
That was nearly a decade ago, so I have no idea how they've changed, but they were great roads back then.

-------------------------------

Mine: 2001.5 S4 6MT - Silver - AWE Stage 3/AWE turbo-back/StopTech/STaSIS/Vogtland - Cared for by WMS

Hers: 2006 A4 2.0t quattro S-Line - Ocean Blue - GIAC 5x

Current Project:
1994 Jeep Grand Cherokee 4x4, 5.2L V8, Mopar ECU, K&N FIPK, Borla headers, Flowmaster 40 series
Almost done: Rubicon Express 4.5" Superflex w/ 32" BFG AT/KO