Paul, You are absolutely right when you said the "best" in all of those polls is nothing more than a joke. I feel there is no such thing as a best poll, just there is no such thing as a best cruise ship or best cruise line. In the end, it always comes down to individual preferences.
All of those so-called polls can be heavily swayed by the type of questions asked. In addition to the same people voting for the same ships year after year, the inclusion or exclusion of questions such as "rate the best past passenger program", "rate the ships reliability" or "rate the customer service" or "rate the welcome aboard process" would skew the results of the poll.
Having sailed on many cruise lines, I guess that I would add Princess to your list of cruise lines, for those looking for a consistently good cruising experience on reliable well maintained ships.