The Stanford University Copyright & Fair Use website has an entire page with examples of court cases involving fair use
Court cases that ruled in favor of fair use:
Rotbart v. J. R. O'Dwyer Co.
Nunez v. Caribbean International News Corp.
Court cases that ruled against fair use:
Religious Technology Center v. Lerma
Worldwide Church of God v. Philadelphia Church of God
'Fair Use Question of the Month'Center for Social Media
Stanford University Copyright & Fair Use Center
BitLaw: Fair Use in Copyright
A Fair(y) Use Tale
Chipmunk tackles fair use rights
JibJab and "This Land is Your Land"
George Harrison "My Sweet Lord" case - Excellent explanation of this widely known case
Happy Birthday to You - It IS covered by copyright!
It's a Wonderful Life - This movie was in the public domain but is now back under copyright protection