Okay, so you're probably looking at a river-play boat or a river runner. New boats that may be good to look at are:
Wavesport EZG (be wary of faulty plastic)
Used boats to look at include:
There are many more boats that would be good. Most of these boats come in multiple sizes. Any more information on what you want to do with the boat and what kind of attributes you like in a boat would help narrow things down but the big thing is DEMO, DEMO, DEMO. You want a boat that is comfortable and everyone fits in boats differently. Plus any shop will give you credit towards a purchase if you demo.
"The world would be a better place if everyone kayaked."-Brad Ludden (Valhalla)
"You only get one chance to run a drop blind."-DD