None. Every choice I made and all it's consequences made me who I am today and I am happy with who I am.
What was the best decision you ever made?

The birth of one of my kids. Almost lost my wife when she got puerperal fever. The aftermath forced me to give up my quite successful career in IT and become a stay at home dad. By the time I was ready to find a job again I'd been out of IT for some ten years, way too long to get back in. No regrets though, I did it because I loved my kids (still do) and though it didn't make me richer financially, being there with my kids growing up did enrich my life.
What experience did enrich your life the most?