I attend both and find comfort and help in both. I take the words "take what you need and leave the rest" to heart.
If there is no Nar-anon group in your area, I would highly recommend Al-anon. If there is more than one Al-anon meeting in your area, I would also highly recommend that you try them all until you find the group that is best suited to your needs and you feel most comfortable in. Unfortunately, I think many people make the mistake of going to just one meeting or just one group and making a determination based upon that limited experience that it's not for them. Each group has a different feel and focus.
For me, the programs works. I work hard at it and I am amazed at times with my own progress (and my own backsliding lol). It has changed my life.
gentle hugs
ke