Dealing with a negative family member…or a person who just likes to put you down

Well, I will start by saying that you are definitely not alone in your situation, as clearly shown in many of the above posts.
I am the youngest in my family, have one sister, one brother, and one asshole brother.
For most of my life I have had a reasonably good relationship with the asshole brother until about 10 years ago when my wife and I moved away to be closer to my mother who is now 91 years old.
We have not had any contact for 7 or 8 years now and I believe it is because he feels that I'm trying to take control of her life. Nothing could be further from the truth, she is still very independent, lives in her own home and remains extremely active in the community.
I rarely have any contact with my sister, she blames my mother for every single thing that has gone wrong in her life and is a very negative person. I don't need that in my life, have enough problems of my own.
Do what makes you happy, because it will piss off your asshole brother, and live your life for you.