Look at Vacations to Go, Expedia, orbitz, Travelzoo, Travelocity and Overstock.com to see which ships are cruising out of a Southern California port (and this includes San Diego) at what price. Then see a travel agent experienced in cruises and listen to what they have to say but do not be rushed into making a decision.
All of the majors will provide you with a fun cruise. Some lines cater to younger persons but all have reasonably good food, entertainment, and service.
We did RCL Mexican Riviera last December out of Port of LA. We have also done HAL out of San Diego to the Riviera. We (both in 30's) like RCL because it is not too coservative but not too wild either. HAL was a very relaxing cruise to be on, but we had more options on RCL for later night activities. JMHO though.
We did the CCL Mexican Riviera out of LA on the Pride and are going to do the Acapulco cruise on CCL out of San Diego. The Pride is wonderful and I hear the same on the Spirit. I would definitely recommend either!
You have a lot of options. My suggestion is to consider a cruise on one of the Princess ships or Celebrity. These cruise lines will provide you with a nice cruise experience at a very reasonable price. Also, look at cruises out of San Diego as this is a great port in terms of hotels, parking, and access from the Los Angeles area.
We are sailing on Diamond Princess to the Mexican Riviera (Cabo, PV, and Mazatlan) on November 11th. This will be our 4th cruise on Princess. We are in our 50's and looking to just relax and enjoy ourselves.
We started cruising in our 20’s and are now in our early 40’s. We have been on Norwegian, Carnival, Royal Caribbean, Princess and Celebrity. We have done the Mexican Riviera 3 times—twice on Princess and once on Royal Caribbean. Both cruise lines have very nice ships and good food. The age of the passengers is usually a little younger on Royal Caribbean than Princess. I also thought the age of the passengers out of L.A. was quite a bit younger overall than in the Caribbean.
We went on Carnival once 14 years ago and had not been back. We decided to try them again in February 2006 to see if we would like them any better now—plus we were with a big group and their pricing was quite a bit less than the others. I thought the ship was very nice and that the food had been greatly improved. However, I found that I still preferred the cruise product provided by Princess and Royal Caribbean. The reason for this is that we are not interested in all of the smoking, drinking, etc., that is available on Carnival. Also on the Carnival ship that we were on the music in the pool area was always excruciatingly loud.
So that was a very long way of saying that if you are not looking for the wet t-shirt environment, you may be happier on Royal Caribbean or Princess. One nod to Royal Caribbean over Princess on this itinerary is that in the past Royal Caribbean has had a longer port call in Cabo San Lucas than Princess has.
I think you should go talk to a cruise specialist that can qualify you based on your age and your likes/dislikes of what you are looking for in a cruise vacation. All the cruise lines mentioned are all good cruise lines, but are different in their own way. This is why you should talk with a cruise specialist Travel Agency.
I would not describe Carnival as wet t-shirt. I have heard loud bands by the pool, and seen heavy drinking and smoking on other cruise lines as well. It depends on the passenger mix on any given cruise. Shorter itineraries tend to draw livelier passengers.