In the book The Top Five Regrets of the Dying a nurse has recorded the most common regrets of the dying which are:

1. I wish I'd had the courage to live a life true to myself, not the life others expected of me.
2. I wish I hadn't worked so hard.
3. I wish I'd had the courage to express my feelings.
4. I wish I had stayed in touch with my friends.
5. I wish that I had let myself be happier.

Looking at myself, if I were suddenly to come to realize I'd be dying tomorrow, I'd also regret items 1, 2, 3 and 5 (not 4). However, in order of importance I'd say 5, 1, 3 and 2.

Here's the newspaper article where I found this.