I'm sorry, I've never stayed in any hotels in Long Beach. But if you Google "hotels near Long Beach Cruise Terminal", you will get plenty of suggestion. The most obvious choice would be the Queen Mary, which is not that much more expensive than other good hotels in the area, and I understand you get priority boarding privileges when you stay there. (you know that the Queen Mary is right next to the terminal)
I'm sure others have stayed in Long Beach and can make suggestions for you.