ACLU v. Mukasey (PDF): Holding that the Child Online Protection Act facially violates the First and Fifth Amendments. The trial on the constitutionality of COPA in 2006 was a fascinating episode in the annals of First Amendment history- check out Nerve.com's blog of the trial.
CBS v. FCC (PDF): Holding that the FCC's abrupt rule change, used to fine CBS for its Super
U.S. v. Stevens: (PDF): Striking down a federal law criminalizing the sale of depictions of animal cruelty, and voiding the conviction of a distributor of dog-fight videos. The Government unsuccessfully defended this law as closely analogous to laws against child pornography.