Finland
A good way to get to Tallinn or Stockholm - much greener than flying. Lots of services, and all ferry terminals are walking distance to city centre accommodation. However, you should book a cabin if doing the overnight ferry trip to Stockholm, as the bars, cafes and clubs are terrible, and there is nowhere quiet for you to sleep in a chair.
Viking Line Terminal;
www.vikingline.fi/index.asp?lang=en
Search Been there