A cruise can be your worst nightmare, or it can be your best vacation ever. Choose the wrong ship and you could be trapped in a Las Vegas at sea for a week, wandering in search of an empty lounge chair, bombarded by infomercial-style sales pitches, forced to dine with strangers whose idea of a thrill is the ice sculptures at the midnight buffet, and waiting in hour-long lines to get ashore in tourist-jammed ports. Choose the right ship, however, and you could be exploring exotic islands that are tough to access any other way, from a perspective that sheds new light on the country's history and culture. You could be standing in the ocean breeze on your cabin balcony at sunset, with nothing in sight but a sparkling azure sea. You could be enjoying a vacation that combines sightseeing and spoil-you-rotten pampering, minus the stresses of moving from hotel to hotel.