Cruises are not 'all inclusive' [with exceptions]. You will get all your meals and entertainment. You pay extra for alcohol, shore excursions, casino, some spa services, your tips and speciality restaurants. Certain lines like Seabourn are all inclusive meaning that drinks are included [but you certainly pay a premium to travel with them.
All cruise lines include all meals. Water, tea and coffee with meals is usually included although some will charge if you order a speciality coffe or bottled water. It is not usual for alcholic drinks to be included unless you go with a cruise line that does an all inclusive drinks package. Even if you dont get that kind of package, some will offer other types of deals on alcholic drinks, eg 7 bottles of wine for the price of 6. Entertainment is included but some activities may attract an additional charge e.g. e.g. web page design class. As far as facilities go, things like use of the pools, gyms etc is included but things like use of steam rooms/sauna can be extra. All spa and beauty treatments are extra. Some lines will also restrict access to all parts of the ship and dining rooms depending on the class of cabin booked.. For example Cunard do this with the Queens Grill being the highest category on the Queen Mary. I'd suggest that you have a look at the description of the various cruise lines on this site and pick the ones that most appeal to you (in terms of age, ship size, formality/informality, price etc) then have a look at their individual websites or this website, to see what is included in the pric.
Most cuises are inclusive of meals, entertainment and activities. Some cruise lines include tips, excursions and drinks and they normally highlight this in their brochures.
No most cruises are not "All-inclusive" although on some you might be offered a package deal or if you spend enough on the lines like Silversea then all beverages are included. Meals are included in your cruise price but even here many lines have "speciality restaurants" for which an extra charge is made and there are some which allow you one visit to a special restaurant and don't charge. Princess will charge for some extras like ice cream others won't. Many of the facilities are free like shuffleboard, putting courses and swimming but most spas charge for their services (some of them very heavily) but the gyms are free. Acupuncture costs a lot whereas lectures about it are free. Ship's organised tours ashore are charged for on most ships but on Swan Hellenic ships tours are free. Entertainment is normally free but that varies in quality. I have been on Galaxy recently when the entertainment was some of the worst I've experienced with Celebrity whereas on an earlier cruise on her it was quite brilliant. Quite a minefield isn't it? Best thing to do is decide where you would like to go and then decide with whom, then read the small print in the brochures where that is all explained and if you think you can get better elsewhere....then go elsewhere Regards Nei.