Hiroshi Fujioka (Takeshi Hongou, the first Masked Rider) speaks very impressive English. Out of memory, I read that he has a dual citizenship in the US!
Tetsu Nakamura (AKA: Satoshi Nakamura), who's been in many classic tokusatsu eiga (including The Manster and Mothra), speaks great English, and helped out his fellow actors in English-speaking roles.
The late Jerry Ito (who played the villain Nelson in Mothra) also spoke great English (he's also a famous singer in Japan).
That's just a few I can list off the top of my head.