I like this thread, makes you think about what regrets you may have, what life decisions we have made that perhaps if we had to do all over again, we would have made differently, but I think they are a little to personal to post publically, personally speaking that is. Although I will say that I do also regret not spending more quality time with dear departed family and friends.
Regrets are a good thing. I can't imagine any human going through life never making a choice they don't pause to wonder about later. Live life, and learn from it. I believe our "regrets" from our past make us better people for today. JMHO of course.