If you've got four dollars to spare and want a very funny short diversion, I recommend going here and downloading Dr. Horrible's Sing-Along Blog.
Dr. Horrible, the brain-child of Joss and Zack Whedon was released as a live webcast this month, and is now exclusively available through iTunes.
It stars Neil Patrick Harris as Dr. Horrible, who longs to be accepted into The Evil League of Evil, Nathan Fillion as Cpt. Hammer, Dr. Horrible's doltish nemesis, and Felicia Day as the socially soft-hearted love interest between the two.
Hey, my husband rates this as "the funniest thing I've seen all year," so you know you can't go wrong!