Marin County classic
State Parks have made a lot of improvements to Samuel P. Taylor since my first visit in 1994. I like the addition of accessible trails and expansion of ADA compliant spots, all laid out in detail on their website.
Some of the reviews mention that sites are too close together but remember that this is a pretty large park. If you hike in those sites tend to be more private feeling.
Good spot for group camping if you choose and a frequent choice of schools and scouts.
Month of VisitMay