There are basically five categories to cruise lines.
THE ULTRA LUXURY MARKET
These are upscale ships (often much smaller than the mega-liners) that generally cater to wealthy people. Silverseas would be one example. Service and food is truly gourmet (the only real gourmet food you’ll get at sea, by the way). Some of the ships and cruise lines are known to be more “snooty” while others are less pretentious
THE UPSCALE MASS MARKET
These do a wonderful job and provide a cruise experience on a larger ship and, of course, at a higher price than any category, except for the previous one. Crystal would be counted toward the top of this category and probably Celebrity toward the bottom.
THE MIDDLE-OF-THE-ROAD MASS MARKET
All of the big lines would fall in this category, including Royal Caribbean, Carnival, Holland American, Princess, etc. These offer a great deal of value for the price.
THE BARGAIN/SMALLER LINES
This is the most varied category. In this category, Majesty Cruise Lines can give a great experience for short cruises, and it includes the ultra-budget Dolphin Lines, along with lesser-known cruise lines. You must be careful, however, when choosing a company in this category.
There is a projected over-capacity glut of cabins in the industry, already well underway. As in any other industry, be aware that the more financially strong lines will survive, and the smaller ones (with limited financial resources, older ships, etc.) will continue to fall by the wayside as the industry consolidates. You must make absolutely certain that you determine if you’re sailing on a cruise line that is not in somewhat shaky condition, financially speaking.
SPECIALIZED LINES
These include a wide variety also, including barge cruises in Europe and smaller ships (maybe 150 passengers or so) that ply the inside passage to and from Alaska, as well as “adventure” cruising that lines like Renaissance targets.