6. Leonard Almost Blows Up The Apartment With Rocket Fuel
During the popular flashback episode which explains how our four heroes originally meet, Leonard reveals that he attempted to launch Howard's model rocket with actual rocket fuel that he had taken home from work. He actually took it to impress a girl he liked, who later turned out to be a North Korean spy (that too could be an entry on this list, but even a genius will do anything if he thinks he's got a chance at getting laid). Anyway, Leonard adds too much fuel, or something equally dangerous, (all we're told is that he adjusted the formula incorrectly) and the mixture explodes. Fortunately Sheldon manages to isolate the container in the elevator and pull Leonard out of harm's way, thus saving his life and forever cementing their friendship. The fact remains though that Leonard very nearly got himself (and possibly the other three characters) killed and destroyed the elevator, leading to endless stair climbing scenes throughout the series. Granted it was early on in his career, but since he was handling explosive fuel, you would expect him to pay slightly more attention to his formula.
As a wrestling fan I've flown across the Atlantic for the last five years specifically to attend WrestleMania (28 and 30) as well as TNA, ROH, Evolve, Chikara and most recently PWG.
I may have a problem!
But if you're reading my work then you probably love wrestling too, so lets focus on that!