My biggest regret is not recognizing and enjoying the best time of my life as it was happening. To look back in hindsight and then realize that the best time of my life has already passed it quite. Very few people have died wishing they worked more. The guilt you're feeling may end up being a valid regret though, so maybe work on that. Don't feel bad for seizing moments to relax in a.
Read the best ones. I've got two (similar) regrets:
The McKinley Richardson Leak: This Is Only The Beginning
The Explosive Revelations From The Taliyah And Gustavo Leak
* CoomerSU: How To Protect Yourself From This Deadly Malware