in my opinion there isn't a unique answer as there are many conferences devoted to particular applications that are really good but not of general interest. Addressing the largest and wisest, I can suggest a little list of VIP conferences based on my knowledge and my research interests.
IEEE APEC, normally held in USA
EPE (ECCE Europe), held in Europe (EPE association in collaboration with IEEE)
IEEE ECCE, normally held in USA
IEEE ECCE Asia
IEEE ISIE, around the world
I'm sure that you will really enjoy every of those.
in my opinion there isn't a unique answer as there are many conferences devoted to particular applications that are really good but not of general interest. Addressing the largest and wisest, I can suggest a little list of VIP conferences based on my knowledge and my research interests.
IEEE APEC, normally held in USA
EPE (ECCE Europe), held in Europe (EPE association in collaboration with IEEE)
IEEE ECCE, normally held in USA
IEEE ECCE Asia
IEEE ISIE, around the world
I'm sure that you will really enjoy every of those.