R.I.P. Heath Ledger: Not sure who he is?

Heath Ledger (1979-2008) (imdb: http://imdb.com/name/nm0005132/)I'm finding a lot of people really weren't that aware of who Heath Ledger was or that what looks like his best performance ever (in The Dark Knight as the Joker) was about to be unleashed upon the world. Most of my friends (movie buffs as well) replied 'Who?'So I wasn't gonna post anything about him- I mean, he's not a sexy female