Over the past several weeks, several banks have failed, and their depositors paid out by the FDIC. While the FDIC may pay out more than the insured amount, the actual amount of deposit insurance per account at a given bank is $100,000 (or $250,000 for certain IRA's and other similar deferred accounts).
However, depositors can have different types of accounts at the same bank, and their interest in each can each be insured separately up to $100,000. Since the various types of accounts and applicable rules are lengthy, I have prepared a useful summary which can be accessed here.
The FDIC also provides a calculator that can assist in determining amounts insured at a given bank.