I have owned or heard all of the following and in general favor these high efficiency designs
Audio Note AN/E sec
Exemplar Horns
Lamhorn
Beauhorn
KCS SEAS Exotic
Tonian TLM-1
Tonian Classic 12.1 (currently own these)
Stellovox
Magico Ultimates
Klipsch Corner Horns
JBL Parragon
Merlin VSM MXE
Horning Alkibiades
Acapella (not sure which model..ion tweter)
Audio Note AN/E sec
Exemplar Horns
Lamhorn
Beauhorn
KCS SEAS Exotic
Tonian TLM-1
Tonian Classic 12.1 (currently own these)
Stellovox
Magico Ultimates
Klipsch Corner Horns
JBL Parragon
Merlin VSM MXE
Horning Alkibiades
Acapella (not sure which model..ion tweter)