That would be Dred Scott v. Sandford. Just in case you're ever on Jeopardy or Cash Cab.
How about...
Plessy v. Ferguson (segregation)
Marbury v. Madison (judicial review)
Loving v. Virginia (interracial marriage)
Lawrence v. Texas (decriminalizing homosexuality)
Lochner v. New York (regulation vs liberty of contract)
Adkins v. Children's Hospital (regulation vs liberty of contract)
Muller v. Oregon (regulation vs liberty of contract)
Schechter v. US aka Sick Chicken (overturned New Deal)
Parrish v. West Coast Hotel (legalized New Deal)
Regents of UC v. Bakke (affirmative action)
Korematsu v. US (validated Japanese internment)
Miranda v. Arizona (defendants' rights)
Now, most people obviously won't know all those cases (unless they've suffered through oral exams). But most people surely have heard of something on that list. Or at least, most people who are freaking vice presidents of the United States have heard something on that list.
Palin is just embarrassing. "Country First" my ass...