Domaine Eden’s offerings are great. Their '08 Cab is really nice for the price.
Garnet’s Carneros and Rodgers Creek Pinot rock at $19 and $29 respectively. The Rodgers Creek got high praise from AG (91 points). Artesa Estate Reserve at $25-29 is also real nice. Layer cake if you want a sub $20 that’s a cheap general crowd pleaser.