Best school to study Japanese in Manhattan, NYC?

I studied a bit of Japanese, but not at the schools you cite (this may sound odd, but I took a course via the Japanese Embassy in Tel Aviv). However, I considered studying at the Japan Society in Manhattan, and I was impressed.with their course offerings. My guess is that they’d be pretty thorough, and also that you’d have access to their print and audio library, as well as to their exhibitions, films, etc. – and getting steeped in the culture definitely augments learning the language.

You might be able to get info and recommendations on courses in Japanese at the large Japanese bookstore on 41st street between 5th and 6th Avenue (it’s opposite the south wall of the main branch of the NY Public Library, in case I’m getting the street address wrong). In any case, in my experience – look for a teacher who’s a native speaker…