The list of countries is quite long and varied depending upon what you mean by same sex domestic partnerships. Some notable countries include, Argentina, the Netherlands, Iceland, the United Kingdom, and Andorra, in which one can perform the ceremonies, where as Israel only recognizes the partnership conducted in another country Some countries call the association civil marriages, domestic partnerships, same sex partnerships, etc. Each country characterizes and defines the terms and rights differently, so that too will affect responses to your question. Consider researching the United Nations website which keeps tabulated information on such regarding gay, lesbian and transgendered rights. Good luck!