Here's my list (in no particular order):
1. Justice Holmes, Lochner v. New York: Short but effective. In one sentence, Justice Holmes makes his point and guts the majority opinion: "The liberty of the citizen to do as he likes so long as he does not interfere with the liberty of others to do the same, which has been a shibboleth for some well-known writers, is interfered with by school laws, by the Post Office, by every state or municipal institution which takes his money for purposes thought desirable, whether he likes it or not."
2. Justice Kagan, Arizona Free Enterprise Club's Freedom Club Pac v. Bennett: Justice Kagan's introduction is concise and persuasive in ways most legal writing is not. It turns an amorphous constitutional issue into a concrete example.
3. Justice Jackson, Korematsu v. United States: In plain English and with plain logic, Justice Jackson explains why Korematsu's encampment was unconstitutional and dangerous.
4. Justice Harlan, Roth v. United States: Technically concurring in part and dissenting in part, Justice Harlan persuasively explains why the federal government should not have unbounded discretion to outlaw obscenity. And he simply yet powerfully explains why free speech is not a popularity contest: "Many juries might find that Joyce's 'Ulysses' or Bocaccio's 'Decameron' was obscene, and yet the conviction of a defendant for selling either book would raise, for me, the gravest constitutional problems, for no such verdict could convince me, without more, that these books are 'utterly without redeeming social importance.'"
So, what other dissents should go on this list?