Interesting topic...The benefits I have received were not necessarily the benefits I was praying for in my last drinking days, so it's difficult to choose the top 3.
Had I taken this poll one month in (sobriety), I would have chosen physical health, improved functioning in workplace and improved relationships. With almost a year under my belt, the best and most unexpected benefit would be having a real, meaningful spiritual connection for the first time in my life. My relationship with God (Creator, Source, Higher Power...substitute whatever resonates with you) has completely changed my life. Second benefit would be improved relationships, especially with my husband and kids. Lastly, mental health. I have been restored to sanity. Life is good!