No one. If it wont’ effect this timeline then there is no point. If it could affect this timeline I still wouldn’t, simply because it could inadvertently lead to me never being born.
Archduke Ferdinand
Gavrilo Princep who by murdering Franz Ferdinand set the ball rolling for the evils of the 20th Century.
Oliver Cromwell, the Motherfucker. And Nathan Bedford Forrest.
If it hadn’t been for the murder of the Archduke, it would have been something else. Europe was most likely going to go to war – that was just the event that started it all.
Dreadnaught, by Robert Massie is a good book to read.
Another vote for Lenin, although Hitler would have been my first choice.
I’d pay some Dutchman to set fire to Lord Snowdon.
I think it’d be more interesting to bribe some officials and make sure Hitler got into art school, just to see what would happen. (You could always whack him later, if you still wanted to.) 
The guy on the grassy knoll. That way, there’s no doubt Oswald acted alone. 
What happens when the killbot can’t find the assigned target?
I’ve already done this.
Except that I didn’t see a need to make my killbots invisible…
Doesn’t “Anyone alive today(and don’t try getting around it by bumping off their ancestors)” pretty much mean you can’t kill anyone with living descendants? And given that like what? 1 in 200 people alive today are descended from the Great Khan, doesn’t that eliminate him from consideration?
No problem. Mine will be John F Kennedy. In Dallas, ten seconds before Oswald.
John Wilkes Booth. If Lincoln lives, Reconstruction goes much quicker and with much less bad blood between north and south, changing the dynamics of politics from then till now.
Good point, A good person might bring about bad consequences
Likewise, an evil person can bring about good consequences. If the American revolution had been won by someone fertile, then we might have ended up with an heridetry absolute monarchy, and the world would lose early modern democracy’s city on the hill.
Good point… I didn’t think this one through… anyway, please pretend this doesn’t matter, pretend all their OT childerne were illegitimate children of other men.
Since Paul is against the rules, I’m going to go with Emperor Constantine.
Josef Stalin.
Nikola Tesla, shortly after birth. Just to see how much it would set back modern technology.
My grandfather. I love paradoxes.
That sounds like something Zaphod would have done, not Ford.
Frank Sinatra. I heard he was a dick. Or Bing Crosby, because he beat his kids. Or Bob Hope, to save us all 50 horrible schlocky militarized vaudeville shows.
Fuck, lemme take out the Rat Pack.
Ronald Reagan after his last child was born, but before he was governor of California, so it will fit in the rules. He had a horrible influence on American and world politics. What a tool.