What's your preference? Movie's or Music? Do you plan on driving all 5 speakers with your AVR or are you going to get an external amp some day; either 2 channel or multi channel? If your going to just use the AVR, pay attention to sensitivity and impedance specs and you'll probably want to stay away from 4 Ohm speakers. That will limit the choices. Are you thinking floor standers or bookshelf? If bookshelf, are you going to actually place them on shelves? Are the surrounds going on the walls? If so, you'll be limited to front ported speakers to achieve proper bass response.
Most important, as the above posters pointed out, what speakers do you already have and what are you familiar with? Each design and type of driver provides its own unique sound. Find out what your preference is - all types, including ribbon tweeters, are available in your price range.
As you can see, there are many factors to consider before a recommendation can be made. So start asking yourself the above questions so you can arrive at speakers that are best for your needs. And start auditioning!
