It all depends on which level of service you are getting. A set top box is not required for the basic television service. However, if you plan on purchasing the digital services, you will need a set top box for each television. There are currently three different choices of set top boxes to choose from. The price will vary depending on which types of set top boxes you choose to lease. A Standard Definition set top box will cost $3.95 per month, High Definition at $9.95 per month, and a Digital Video Recorder (w/ HD) for $12.95 per month.
Go here for a list of the prices for each FiOS TV package -
http://www.fiberexperts.com/service-packages.htmlGo here for a list of the channel lineup (Keller, Texas - But will give you an idea of channels available) -
http://www.fiberexperts.com/channel-lineup.html