The 2009 Oscars would not have been nearly as awesome without Hugh's phenomenal opening number. Incidentally, Anne Hathaway's performance alongside him (briefly) was so well received that she later went on to host the Oscars as well.
At the end of Van Helsing, Hugh Jackman was actually naked after he turned back into a human being, but the effects team had to add on pants to the final cut of the film because, allegedly, the crowd during an early screening couldn't focus on the sad moment because of his body.
Hugh Jackman was genuinely naked when he filmed one of the scenes in X-Men 2 so the crew decided to play a little prank on him. He ran down the hall and turned a corner only to find the entire female cast present to make catcalls and moon over his naked body.