AeroVironment are the world-certified Rock Stars of UAV. Remember the Gossamer Albatross? that's them, and they've been going strong the past 30 years. Here's a page describing their UAV solutions... this is the real deal, used by the Marines in Afghanistan and by NASA. More on these later.
Unfortunately, you can't buy them... but there are clones available at reasonable prices (body only, no UAV). Check it out: