Celebrity, the first to grow real grass and build a serious art collection, has long been one of the most innovative lines. These cruises draw couples, families, and groups who want style and comfort without luxury-line fares. The wide scope of daytime activities ranges from the educational (think technology classes) to the playful, such as water volleyball matches with ship officers. Impressive specialty restaurants include small-plate-style Qsine — which serves sushi “lollipops” — and the Lawn Club Grill, where you can sear your own meat.