Bill (from Kill Bill), Wild Bill Hickok (from Deadwood, as well as Frank Lundy on Dexter and Lou Solverson on Fargo), and Lewis "Not Named Bill" Slotnick (from Revenge of the Nerds) are all brothers. Yep, the Carradine bros David, Keith, and Robert are all part of the same acting family, and no, I'm not sure why the nerd one doesn't have any characters named Bill.
Not only is Wild Bill Hickok related to Bill and Sam McGuire (Lizzie McGuire's dad, who is also not named Bill), but he's also Martha Plimpton's dad! Remember Raising Hope? That was an okay show, but would have been vastly improved if Martha Plimpton's character was named Bill.
Some timey-wimey weirdness here - the 5th Doctor's daughter in real life, Georgia Moffett (NO RELATION TO STEPHEN MOFFETT - it turns out Peter Davison's actual legal name is Peter Moffett), played the 10th Doctor (David Tennant)'s daughter, Jenny, on a 2008 episode of Doctor Who entitled "The Doctor's Daughter." Tennant and Moffett (again, not Stephen Moffett) hit it off and were later married, making the Doctor his own son-in-law (and, uh, married to his own daughter).
Yep, Melissa McCarthy, who you may remember as "the pudgy, sorta wacky" character from Everything She's Ever Been In and Jenny McCarthy (aka "the worst human being you've ever masturbated to") are cousins!
We'll let you decide which is worse: Tammy, or your kids all contracting polio?