i went with my family to an all-inclusive this winter as opposed to a cruise, which we usually go on during that time of year.
all-inclusives are great for just relaxing and chilling out by the pool with free drinks (the free drinks are probably one of the major advantages over cruises). everything's included, so you don't need to worry about doing anything that will cost extra.
cruises, on the other hand, i find you can relax by the poolside like at resorts, but you are also very active when it comes to different ports of call. cruises get you on a lot of extras, like excursions, photos, drinks, etc, though.
cruises have a different social atmosphere, too. everyone's getting on and off and the same time, whereas people are continuously coming and leaving at resorts. people seem to let loose a lot more on cruises than in resorts, too, which makes for a more fun and party-like atmosphere.
overall, my vote goes to cruises. you get to see a bunch of places as opposed to one, the fact that you're on a ship makes it more exciting, and the cruise culture is definitely a lot more exciting than that of resorts.