I haven't been on all of them but really its all about price. It depends on how much you want to spend, how long you want to cruise and where you want to go, and what you like to do.
Life is too short to let the ship of your dreams sail without you.
Carnival Destiny Feb. 2006
Carnival Fascination Feb. 2007
Royal Caribbean Grandeur of the Seas Feb. 2008 The DTW & MsBJ tour
Carnival Valor MsBJ and Dina Feb. 2009
Carnival Glory MsBJ and Dina Feb. 2010
Carnival Dream MsBJ and Dina Feb. 2011
I think the only two Carnival ships sailing outta Long Beach are Paradise and Pride. I certainly favor the Pride over Paradise for the ship and itinerary. BUT, I wouldn't call any Carnival ships "luxurious". Funs is their mission, and fun they are!
I have sailed both RCCL and Carnival and I think the RCCL ships are much nicer. My DS pointed out that there were not as many activities scheduled, as compared to Carnival, but I always felt there were more than enough options while on board. (DS and DIL did Carnival for their honeymoon and then RCCL with my DH and I the following year.) The food and service were comparable. There were fewer children on RCCL. As you said, options, options.... Read some of the ship reviews to give you a better idea. You will find lots of different opinions, so you finally just go with it! I promise you, you will not be disappointed.
Mariner of the Seas
Carnival Magic Bloggers Cruise 5
Mariner of the Seas
HAL Statendam Alaska Cruise Tour - 09/09/12; Disney Magic - 12/01/12; Allure of the Seas - 05/26/13
Read some of the ship reviews to give you a better idea.
This is a great suggestion! Go to the "Ship Reviews" section here and read Ann's reviews and the Reader's Reviews.
I'd also suggest you find a Travel Agent who is a Cruise Specialist. They can aim you in the right direction as far as your tastes and your budget.
We haven't sailed RCCL, but from talking to my TA and reading posts here on CM's, I'd say they are definitely more upscale than Carnival.
Have a wonderful cruise, no matter what you decide!
"A truly happy person is one who can enjoy the scenery on a detour."