I don't know if they are overly interesting, but I'll share two.
1) President Theodore Roosevelt, a distant cousin of mine, interacted with Senator Matthew Stanley Quay, a distant cousin of my wife. I guess it goes without saying that a President and Senator would interact, but the President did ask "pray tell how is Boss Quay doing?" when Quay as on his death bed.
2) I am adopted and have known my whole life (story above is my "adopted" family). I picked up genealogy as a hobby about 10 years ago, when my first kid was born. To keep a long story short, I was able to use a combination of a DNA test, resulting in a few key cousin matches, with some standard genealogical sleuthing to find both of my birth parents earlier this year. We actually hosted my biological mother over for dinner a few times last month as she was visiting PA from FL. As part of that, discovered 6 half-siblings! Unfortunately, my biological family hasn't been as interesting to research as my adopted family (almost all lines of my adopted family extend back in the U.S. pre-Revolutionary War whereas three of my four biological lines are off-the-boat from Europe in the early 1910s - the one that extends back further is pre-Revolutionary, so there's a lot to uncover there!). It has been cool, though, to use DNA to confirm various biological family tree lines (and now many of the surnames make a lot more sense!).