Azamara. Small ships, amazing crew and staff, no tipping at all, great food, all drinks are included, no nickel and diming. Port intensive cruises with late night departures or overnights. They don't do point-to-point like other lines so you can combine back-to-back cruises for a longer itinerary. 5 star without the luxury prices. And tables for two in the restaurant if you want. The only downside is the small bathrooms in anything other than the higher suites.
Azamara is the best.