1751- Prince Frederick, eldest son of Britain's George II and heir to the throne, was killed when hit in the chest by a cricket ball and died of a lung abscess. As a result Frederick's son became George III (the guy who lost half of North America in the Revolutionary War).
1760- Nine years after his son suffered death by cricket ball, George II died of injuries sustained when he fell off the toilet.
1814- Nine people died in the Great London Beer Flood when 1.5 million litres of beer burst out of a Merx & Company Brewery storage facility (I fully believe that the Canadians reading this are nodding their heads sagely muttering, "but what a way to go, dude.")
1912- Paris tailor Franz Reichelt wanted to test his "coat parachute" from the top of the Eiffel Tower (I think you see where this is going...). Authorities approved his test--with a dummy--but once at the top Reichelt impulsively decided to test his invention himself. It didn't work.
1926- Englishman Bobby Leach, who was the second person to survive going over Niagara Falls in 1911, died when he slipped on an orange peel. Gangrene set in after Leach broke his leg and the limb was amputated--but he died anyway.
1983- Playwright Tennessee Williams choked to death when he swallowed the cap to an eye drop bottle.
1993- Toronto lawyer Garry Hoy was demonstrating at a party how strong the windows on the TD Centre were. He ran at the window once...and then again, at which point the window gave away and Hoy fell 24 floors to his death (pity he wasn't wearing a Reichelt coat parachute).
There were a couple of deaths that involved horses and sex...one in particular involved a "Mr. Hands". You'll have to link to the article for the gory details as I'm trying to keep this a PG rating.