The Pennsylvania Public Utility Commission posts supplier offers at http://www.papowerswitch.com/
The Pennsylvania Office of Consumer Advocate also publishes an online monthly price guide at http://bit.ly/1NcSefF. They'll mail it to callers for free: 1-800-684-6560.
The New Jersey Board of Public Utilities does not compile offers from competitive power suppliers. Legislation currently under consideration would require the public utilities board to create a website for comparison shopping.