Yeah Calgon is right again as usual.... i too believe there is no "bad" cruise, only some that shine more than the others.
For me personally I rather enjoy the western caribbean cruises. I am booked for another western cruise in may, and am contemplating a southern for the fall. The eastern caribbean doesn't thrill me much as there isn't much to hold my attention. Eastern cruises are widely known for their beaches and shopping. Which if i wanted to lounge on a beach i would do it in Sanibel or Siesta Key instead. If i wanted to shop i would go to Downtown Disney...
I guess each segment of the caribbean has it's own attractants/detractors. For me the western caribbean just has more things to do aside from the normal touristy stuff. I mean don't get me wrong, the western has plenty of touristy things to do as well, but there is also alot more to do in the western caribbean ports and surrounding areas than the eastern. Far easier to dive into the culture of the area in the western and southern than the eastern for sure. Many eastern caribbean ports are becomming more "americanized" each year. For me, I want just the opposite. I want to be able to see other cultures and learn about their histories, and if possible, experience it to a degree.
Others have their own reasons for choosing a "favorite" caribbean curise destination. I think you should try all of them at least once possibly twice before saying you have a favorite.. Also, when doing different cruises, it helps if you do not critique a cruise against a past cruise. Each cruise is it's own experience and you can find things to "like/dislike" about the next cruise by trying to compare one to the other. It's kinda like the apples to oranges thing... although they're both fruits... they are totally different. Cruises are like that too, each is similar in many ways, but each is it's own voyage.