With Thomson you can get all inclusive cruises and you might be able to do it with other cruise lines too but not sure.
We are going on the Ocean Village in Jan for fifth time and think it is great. The only extras as you say on food is La Luna and Bistro at evening. Tea/Coffee is only chargeable in Charlies bar - but worth it if you like latte and cappuccinos. All staff are great.
Island Cruises. On the Island Escape there is a free upgrade to All Inclusive, which covers the cost of all alcholic drinks.