Two kinds of cases are put before the Supreme Court: appeals from the appeals court and original jurisdiction cases. Original jurisdiction cases are usually between states. There haven’t been that many. Its Wikipedia page only lists about 27 cases.
A lot of cases were over border disputes: New Hampshire v. Maine, Florida v. Georgia, Maryland v. West Virginia, New Jersey v. Delaware, New Mexico v. Texas, New York v. Connecticut, Alabama v. Georgia, Missouri v. Iowa, Rhode Island v. Massachusetts, United States v. Maine, & Virginia v. Tennessee.
Marbury v. Madison formally established the difference between the executive and judicial branches of government.
Oregon v. Mitchell & South Carolina v. Katzenbach were both cases that involved voting rights. The former about a state’s obligation to conform to a voting act for federal elections and the latter challenging the constitutionality Voting Rights Act of 1965.
Pennsylvania v. New York was a particularly unique case because it established that if Western Union had a money order between two states that was unclaimed, the unclaimed amount should go to the state where Western Union is incorporated: New York.