All three parts of Dr. Horrible's Sing-Along Blog are now online! Watch it for free and risk slashdotting their site again, or buy it from iTunes for a paltry four dollars. C'mon, skip the Starbucks for one day and do the right thing.
Just in case you've been living under a rock and have no idea what I'm talking about, I refer you to Penny Arcade's Tycho, who describes Dr. Horrible as "a supervillain musical written by Joss Whedon, starring a bunch of awesome motherfuckers. Why are you still here."