First, seek the help of a Cruise Specialist as they can be invaluable with providing information on each of the cruise lines.
As for which one is best for you, that's really a personal choice. As one of my favorite expression goes, "What one person loves, another will hate." So just because one person loves a particular cruise line, does not necessarily mean it's the best one for you.
Now, with that said, each of the ones you've talked about offer a completely different experience. For example, Carnival and NCL have cheap prices for a reason. RCCL is more expensive and Princess is even more expensive. It really depends on what you're looking for and the type of experience you want.
If your husband is use to Westin, he won't like any of these as they are definitely a huge step down in quality. Crystal, Regent, and Seabourn would be more of his liking, but your kids would not like them as there aren't alot of amenities for them. And as all of us parents know, if the kids aren't happy, the parents aren't happy.
As for amenities to keep the kids occupied, it's really tough to beat the Oasis-class ships of the Royal Caribbean fleet. They are the largest cruise ships in the world and offer a boat-load of amenities (pun intended). The new ships in the NCL fleet have alot to offer, but may or may not be to your liking.
You basically can't go wrong with any of the new mega ships, but the quality and experience is going to be different depending on the cruise line.
Talk to a qualified Cruise Specialist and let them provide information for your consideration. Just avoid those who start 'recommending' things to you. Again, what one person loves, another will hate, and if they're recommending, it means they like it, but you may not.
No matter what you decide, once you've made your decision, just go with it, enjoy it, and have fun because you're doing it together as a family. And, after all, that's the most important part.