Tajiri is the best since he started from scratch, and pushed the Gameboy to its limits.
Masuda and Ohmori are responsible for adding the most retarded shit and babbifying the franchise as a whole.
Other three are decent, but are just springboarding off Masuda's abortions and fixing their problems. I think HGSS was the biggest "love letter" to the longtime fans rather than being the half-assed remakes that FRLG and ORAS were.