TOD:
As far as regular sickness, the worst I had was when I was in my junior year of college. I was on a liquid diet for 2 weeks. I could not keep any food down.
As far as quirky sickness, after I graduated, for some reason, I came down with chicken pox. That ruined most of my summer. Having chicken pox as an adult is horrid. Without being graphic, let me just say that it will show up everywhere, even where you'd think it was impossible. I had red marks afterwards, but no real pox marks. It was tough not to scratch, and even worse, the heat of the summer intensified the irritation and discomfort.