In the last year, I have purchased 3 new sets: Bridgestone Ecopia EP100 on the Honda Insight, Fuel Max on the 2010 Prius, and just put a set of Bridgestone Ecopia EL422 on the 2008 Prius. Of the 3 sets, I like the EL422 the best so far. Less mpg hit when installed and the cabin noise seem less even when at "normal" operating pressure.
One set came from Tire Rack, one from Discount Tire Direct, and the last set came from a local tire store. The 2008 Prius is the touring with the 195/55/16 size. Discount Tire Direct was hard to beat since there is no shipping charge, but I talked to the manager of a local tire store and asked if he would consider price matching. They matched the online price of $107 per tire which was a great savings over their original price of $140 per tire. Installed, out the door around the door post psi of 29, 31, 33, 33
the total cost was $532.