You cannot get married if you don’t like yourself. No relationship will survive if both parties do not have their own identity with which they are happy. Don’t think you should get married because you can’t bear to be without him.
Most marriages fail because of ineffective communication. Do your arguments end in cold war or serious sulking? Are there any issues that never get resolved? Are you still in that very childish habit of keeping score after fights? Do you feel comfortable in stating your needs and do you feel that your partner understands you when you express your needs?
People get married for the emotional security marriage can offer. However, one partner or the institution of marriage cannot make up for the emotional or psychological needs you might have due to other unfulfilled aspects in your life, be it relationships, your career or boredom.
Have you decided how your finances will be handled? Are both parties satisfied?
You don’t have to like all his friends, but do you get along with most of them. Do you like his parents?
Are there any sexual issues? Marriage tends to turn any previously minor issues into major ones. Are you happy with the amount of affection you receive?
This is such a simple question, but do you have fun together?