Catalina is absolutely the way to go!
In fact, if you have not already looked at this Catalina thread, here is the link:
http://www.disboards.com/showthread.php?t=2152282. I posted some pictures and also gave some info about what to do there and how to get the Free Visitors Guide/Vacation Planner/magazine.
It is a great one-day (or more) trip, and instead of the glass bottom boat, I would recommend the Sub (the semi-submersible) as you actually can see more sea life and sharks and things. I also recommend the Flying Fish tour and the Cruise to Seal Rock. Renting a golf cart is GREAT!!!
I live in the Hollywood/Beverly Hills/Miracle Mile area - near LACMA and the Tar Pits and the Farmers Market and Rodeo Drive and Hollywood Boulevard - and I STILL say skip all of that and do Catalina. It is well worth it.