I can't think of anyone in my family that I know (it's a large family...I'm not a family person) who has a sucessful marriage. All of them have broke up, or got 2nd+ marriages.
I don't agree with marriage for people who aren't religious, so I doubt that I will ever get married. I know it is a lot easier for morgages/banks etc but it's not essential.
I don't want kids. I never have done. When I was growing up my Mum fostered and so there were always younger children around, and now I have a baby (ok he's 3 now) brother. His Mum isn't what you would call smart and so I often try to teach him manners and look after him. I don't want to have to do it again full time.
A friend of mine put it another way..for the price of a kid or two you could get a good ferrari.