I like all antennas, but if I had to pick a special favorite it would definitely be the reflector antenna.  I think it is so amazing how they can just move the radio frequency waves (RF) around in space using a shaped lump of metal and manipulate it into something useful.  They are also the antennas I have spent the most amount of time designing, getting manufactured, testing and interpreting the results of.  However, they are probably not the first antenna that comes to mind for most people, so read on and learn more about them.