Some more:
What if Eric Clapton actually tracked down his biological dad?
What if that cigar killed Fidel Castro?
What if Bob Marley agreed to have his toe amputated, and survived his cancer?
What if Grant Imahara were still alive?
What if Edward Longshanks' eldest son wasn't a faggot?
What if FW de Klerk beat Nelson Mandela?
What if Rosa Parks stood up?
What if half of Liberia were part of America, 50-100 years after the capital Monrovia was founded - Maybe call it South-Western Liberia?
What if Alexander the Great didn't get sick and die?
What of Julius Caesar not only survived, or escaped his assassination attempt, and punished, by death, or exiled the Roman Senate who wanted to get rid of him?
What if the Germans found out about the development of the first tanks, during World War 1? This is a fun fact I'm sure a number of you know already, due to my posting about early tanks on another thread, but tanks get their name for a covert secret name, and the Germans actually bought it: they thought British forces were making fishtanks in a warehouse.