That's a tough decision - all of the ones you listed are great but it's really what you and your fiance like. I've been on Royal Caribbean and Celebrity and loved both but we would love to try Princess. RC has a lot of honeymooner's on it. Celebrity has more of an older crowd but the ships are very elegant and the food - out of the world. I'm partial to RC b/c my husband and I had our honeymoon on one of their ships but it's really whatever you decide - best price, best time to go, etc. You won't be disappointed with a cruise!