I moved to Southern California a few years ago, and have been fascinated with whales and whale watching after living in landlocked states my whole life. I have gone out with most of the whale watching companies, and Dana Wharf is absolutely the best.
Went out again yesterday, and we saw at least 5 grey whales (hard to tell since they were swimming together), and hundreds of dolphins. Even though I've now been whale watching at least 10 times, it's still a thrill, and Dana Wharf does a great job of providing education about the animals and ocean in SoCal.
I should mention that I've also gone out and not seen any marine life (foggy, etc.). When that has happened with other companies they really talk up the "bird sightings", which are interesting, but not really why most people got on the boat. Dana Wharf is excellent in that they give you a Whale Rain Check if this is the situation so that you can come back another time. And if you're wondering what your odds are, check out their website to see the whale counts for the days and weeks leading up to your trip.
Truly recommend this company over the others in Orange County. They're local, dedicated to the community, and care about marine life and passengers, alike.