The other issue with this question is that there are not that many people that have experience with each of these cruise lines. In fact many people only cruise or have cruised with one line. So, any response you get from this poll would be un-naturally skewed towards the most popular cruise lines. I consider myself a fairly seasoned cruiser, but I have only cruised on 3 different lines. And I am not a coffee expert, I drink whatever coffee is available and I am not sure what to consider good coffee. For instance, I don't care for Starbucks coffee. Too strong for me. But I will drink it. The odds of you getting coffee experts AND cruisers that have sampled many cruise lines is remote....
Carnival Cruise Lines:
Fantasy 90, Celebration 95, Victory 05, Conquest 05, Spirit 6/06, Freedom 6/08, Holiday 7/08, Victory 6/09, Valor 9/09, Dream 6/10, Splendor 8/10,Conquest 8/11,Magic 11/11,Triumph 4/12,Spirit 7/12,Freedom 11/12, Triumph 2/13 - The fire cruise
NCL Dream October 2006, RCCL Mariner OTS June 2007, Celebrity Silhouette 2013