I have a KFL (Special), two Fogger's (one wide chimney, one narrow), and an Aga T7
For me, the KFL is my favourite for quality of vape, the Aga T7 comes second, and the Foggers 3rd.
The Foggers come third IMHO as in my experience, you have to go sub ohm (or whack the power up on a regulated device) to make them perform, and then they make some great clouds.
I have also heard very good things about the Taifun GT, and the GP Heron (or Heron clone).