It all depends.

Mortgage brokers should offer a complete selection of mortgage loan products from most lenders at the most competitive interest rates. If you are a well qualified borrower looking for the best rate, don't guess, just compare rates with brokers and banks to see who has a better deal. Just make sure you are comparing apples to apples by checking all fees and charges associated with the transaction.

If you think you will have trouble getting approved for a mortgage loan because of credit problems, income verification problems or other issues, a broker will probably have more programs from more lenders available so you will probably have a better chance of that broker finding a loan program to fit your needs. On the other hand, mortgage lenders such as banks sometimes have what is called "portfolio lending" capabilities which means they can sometimes offer loan approvals even when a borrower does not quite meet qualifications.

The lines between brokers and lenders has become blurred in the last few years. Many mortgage lenders and banks sell their loans to the same investors and lenders that mortgage brokers place your loan with. Where you can get the best deal actually depends as the market continues to change.