I am a teacher so when our travel agent suggested a cruise for our 15th anniversary and my 40th birthday - we wanted a cruise that did not have a lot of kids. We went on Royal Caribbean. It was during spring break and Easter so there were a lot of kids - but less than the other cruises we have taken. The service and food was amazing!
My suggestion is you may want to consider a balcony room. We loved it and it was so relaxing! We watched the sun come up over Cozumel and we also sat out on the balcony at night watching for other ships - it was wonderful.
2008 Navigator of the Seas
2008 Carnival Inspiration
2009 Disney Wonder
2010 Carnival Conquest (June)