We've cruised a few times, both in large groups, and as a couple.
For a large group, with different ages, you need to take a few things into account.
- Kid Programs
-Entertainment suitable for all ages
We've been on Carnival, Royal Carribean, and Princess... I've talked to people who've traveled with Disney and Norwegian, and my parents have traveled on Celebrity and (their favorite) Lindblad.
Carnival is geared towards families and fun. Unfortunately, they are also geared to a younger party crowd. Pools get crowded with people having a very good time. It's fun.. but maybe not the best atmosphere for Grandma? or little people.
On the other hand, they are rather inexpensive, and therefore, more affordable for larger groups of people.
Royal Carribean is a bit more "upscale' than Carnival. They have pools, and entertainment geared towards everyone. The dining room is good, food is pretty good, and not too stuffy for the little people. Decent kids programs.
Princess The most recent cruise we took was with Princess. Our group ranged in age from 5 to 73. Everyone seemed satisfied. Food was good, dining room catered to the little ones as well as the big ones. The pool areas were nice, we tended to stay near the covered pool as it was quieter and more family oriented. Entertainment was good- music shows, magician (ok, he used off-color language...) and dancers.
GREAT kids program.
Downside- a bit more expensive, and on the cruise before this, there wasn't nearly enough security to handle the vast numbers of children that were onboard for spring break. Also, there are no lifeguards at the pools.
Disney Cruise Lines Our family has not yet taken a Disney Cruise, but we have friends who have. They say the ships are super nice, but are really geared to the younger (read.. under 10) set and to super Disney Fans. She told me her teens didn't have as much fun as the 8 year old, and she was overwhelmed by the disneyness of it all. But if you are a fan, or want a very kid oriented cruise... give it a whirl.
Celebrity Cruises Upscale, super nice ships, perfect for adults. Kids... not so much. They do have kid programs, but this cruise company is really geared more toward grown ups.
Lindblad CruisesTalk about a dream cruise for nature lovers. These ships are small... very small... under 200 passengers... No giant showrooms with dancing girls, No swimming pools with slides BUT they are all inclusive, and they are loaded with gear to take you on adventures to places you can only find in National Geographic. In fact... they work with National Geographic. My folks have sailed with them a few times, and we plan to join them some day. It's pricey, but what other cruise ship will let you take a kayak off the back of the ship to see the whales, and then photograph them with the help of a National Geographic Photographer. No kid's programs...but the family will have a great time if they like real nature and adventure, not the kind that comes in a can. These cruises are pricey though...