wow, this is really "It Depends" question
It's hard for me to rank the ships except for the Dream - she's dead last in my book - But I have not been onboard since January of 2013 0 prior to dry dock
Fantasy has all of the bells and whistles AND Satellite Falls
Magic (my first ship), has the nice upgrades to Shutters and Animators

and the AquaDunk and Twist and Spout. BUT she has that abomination that is the atrium (ugh!!!)
Wonder - Upgraded Shutters and still has the original atrium (two staircases and the Chihuly chandelier and the best overall service we've received in the fleet. This is even with the best server that we have had on the Fantasy
Itineraries - We like going to NEW Places!!! and the Longer the Better so...
Panama Canal - probably going from the East to West - keep adding hours vs taking them away (Been Both Ways)
Med Cruise - Was Awesome, our first trip to Europe as a family, but August - too hot and way to humid, but the trip was still awesome
Northern Europe / Baltic - Every Stop was new to us - really cool. So sad that our daughter that loves European History was not able to go with us
Alaska - only 7 nights, but it WAS Spectacular
San Juan / Southern Caribbean - lots of fun in the sun / watersports / zip lines and history on the islands
Transatlantic - I've never been but many people love them
so Putting it all Together
Magic and the Baltic's
Wonder and the Panama Canal Transit
Fantasy - Western Caribbean (but Eastern is great too)
Dream - well it would have to be a 4 nighter, our 3 nights was Crazy with Crazy Hurried People
"Honorable Mention"
Wonder and Alaska
Magic and the Med
But the real thing that makes your (my) cruises special is the people
the Serving Team
the Room Steward
the Club Host
the Cruise Staff
the Pool Deck Crew - servers and towel guys and gals
the Entertainment: The Shows, the Specialty Mainstage/Night Club performers, live onboard music (I LOVE Clara Oman - piano)
the Cruise Director (most of the time we actually get to visit with him or her)
Guest Services for those times when issues arise
and even the Scrape, Paint, Varnish and Power Wash Guys - when they are whistling Disney Songs when you pass them, it just makes me SMILE!!