"California adventure" definitely isn't worth it, but Disneyland itself isn't bad once.
I would hit Universal studios instead for the jurrasic park ride, unless they are extremely young or all girls, as it is a very male demographic'ed park.
California adventure was the best part of Disneyland. I would check in advance if any of the rides are under construction, the three times I've been there over the last 15 years, the Matterhorn and Space Mountain were always down and Tinkerbell was on vacation. I believe they stopped having Tinkerbell "fly" recently, though.