There are 7 attractions at Disney California Adventure we rate as "Not To Be Missed":

Not To Be Missed at Disney California Adventure
Cars Land Radiator Springs Racers
Grizzly Peak Grizzly River Run
Soarin' Over California
Hollywood Land The Twilight Zone Tower of Terror
Paradise Pier California Screamin'
Toy Story Midway Mania!
a bug's land It's Tough to Be a Bug!

Not To Be Missed Attractions at Other Parks