ANA-Average legroom, large lavs, friendly crew, food used to be good, but went downhill. I'd give them a 9/10
ANK-Avg. legroom, friendly crew, lots of amenities for a short flight, excellent. 9 1/2 out of 10
JTA(Japan TransOcean Air)-Avg. legroom, good crew, used to have lots of amenities, but now none, average.
Northwest-Avg.Legroom, very friendly and helpful staff, sometimes excellent, sometimes decent food, old fleet, and not much amenites compared to some other major US airlines. 8/10
Southwest-Sligtly better legroom on 737-700, funny crew, cramped lav, food is very little, but not bad peanuts and pretzels, very cheap 8/10
I'd say ANK was the best. I've only flown 35 minute segments between Okinawa and Miyakojima, Japan, but they give lots of service and amenities for such a short flight.