(Most of these will be from my dad's family because my mom's family tended to keep their legends to themselves!)
1. My father joined the Navy at the age of 15 to serve in WW2. Legend has it that the recruiter told him he'd need his father to sign for him and pointed to a homeless guy across the street and said "Isn't that your father over there, son?". My dad got the guy to sign the paper for him. (I found this was true in military records!)
2. My father was forced to go by a different name in school than the name he was born with and used the rest of his life. (Long lost cousin only knew of him as "Uncle Charlie" but my dad's name was Louis)
3. My father was kept in the basement by his mom and step-dad because he wouldn't disavow his natural father. Said natural father was a bigger dirt bag than one would want to admit being related to, by the way.
4. Legend has it that my paternal grandfather's siblings included three nuns and a murderer.
5. My father's step-father, Malcolm, ran away and joined the circus when at the age of 12. He later became a semi-famous boxer on the East coast.
6. My mother's paternal grandfather, Jesse, was one of the first chiropractors in the US. He wrote two books that were never published, one on chiropractic and one on his childhood and healthful living. He lived to be 104 (if I remember right).
7. Jesse didn't believe in eating white flour or white sugar. He only violated this once a year on his birthday to eat apple strudel.
8. Jesse's first wife died from the flu leaving him to raise 2 & 4 year old boys. He left them with women called "the aunts" in rural PA and went about his business in Philadelphia. He was apparently quite the player, and even though he was married more than 5 times, he was still buried with his first wife, Belva. He said no other woman could measure up to her and that is why all his relationships failed. Personally, I blamed his temper :) Although, I like the sentiment about his first wife.
9. Apparently, my Swedish great-great-grandfather is the result of a 30 year old house servant hooking up with the 14 year old son of her wealthy boss. Supposedly, the wealthy boss built her a cottage to live in and raise her child.
10. One set of my great-great-great-grandparents (Jesse's grandparents) ended up hating each other enough to not only live separately, but they also both told the census taker that they were widows, even though their spouse was living separately just down the street!
And yes, 98% of my family legends are completely dysfunctional. I have a very colorful gene pool.
EDIT: My husband insists that I admit to being 12th cousins with Barack Obama. The End.