7. River Voyager

The Line: Vantage

The 176-passenger, jazz-themed ship will begin Rhine sailings in March with lots of little extras on board. Enjoy the ice cream buffet at the Cotton Club Lounge (which has a retractable roof) as well as movies on demand, complimentary Wi-Fi, and a massage studio. Stateroom amenities include self-defogging mirrors, remote-controlled curtains, and tilt-up, adjustable mattresses.