Kaiji Kawaguchi's historical and political manga (Zipang, Chinmoku no Kantai, Eagle, Gunka no Hibiki, etc.) would be absolutely awesome as dramas. They're long stories, that rely more on dialogue and psychology than action. Each of them covers a broad range of timeless themes (but some would be very timely in this decade, while for example the role of the military is a controversial topic in Japan). If a good director and cast got to bring one to life, that could result in something even better than the original! It's unlikely to happen, but let me dream…