A big misconception about all-inclusive cruises is that they are a better deal. Well, I don't think they are after you consider the total cost. Sure, they are luxury deals with great food and drinks included, but you are still paying for it and then some.
There are 4 6 star cruise lines. Crystal, Regent (formerly Raddison), Silversea and Seabourne. All have some form of all inclusive amenities. Some everything is free, some two bottles of premium liquour of your choice are included. There is one other that is all inclusive but their rating is 5 1/2 stars, Sea Dream Yacht Club. In my opinion the it's the best of the three because all the toys are also included (jet skis, bicycles, waterskiing, champaigne & caviar, you name it). Some are better values than others although all are higher cost per day by far than the mainstream lines. When you factor in that some include excursions and gratuities and occasionally in the off season drop pricing to fill a ship there are some very isolated instances when they truly are a good value. It's very rare but if you ever sail one it's like booking a balcony for the first time, it's hard to ever be satisfied with an inside guarantee again.
The only thing you'll miss is the constant entertainment on the mainstream lines.