There are many awesome Asian cruises, including river cruises. Just depends on how many days you want to travel, where you want to go, and what you want to see.
We recently did a 17-night cruise from Hong Kong to Beijing that was wonderful!
Contact your travel agent, preferably a cruise specialist, and they will be able to help you narrow down the multitude of choices and options.
__________________ Travel Agent/Cruise Specialist w/12 yrs exp and 47 Cruises on 11 cruise lines! Favorites: Paul Gauguin - Tahiti: Uniworld River Cruises - Europe; Celebrity Solstice-class ships; Holland America - 12-nights Baltics & Russia; RCCL - 14-nights Greek Isles, Turkey, & Croatia; Holland America - 14-day Alaskan cruisetour; 10-night Canada/New England cruise; 21 days Hawaii w/7-night NCL cruise; Oceania - 25 days in Asia; more than 3 months touring Europe by train. And many all-inclusive resorts!