I would like to know who makes the most accurate kit of the A6M2-21 zero in 1/72nd scale?

I suggest that you can't go wrong with either Hasegawa's or Tamiya's. That said, Airfix's new 1/72 Model 21 has scored high praise, too.

Wow it sounds like you really can't go wrong with any of those 3 companies. I guess like the old saying just close your eyes and pick one!
Thanks again.

The absolute most accurate a6m2 would probably be Fine Molds expensive and pretty uncommon "ultimate zero" kit. Hasegawas kit is pretty nice, Im working on one right now. The only drawbacks would be the very basic cockpit and one piece canopy, and very shallow wheel wells. However how important those things are is up to you, its still a nice kit and fit has been excellent.

Airfix looks a litlle nicer but I dont have hands on with one yet so I cant comment but its worth a look as it appear nice, well detailed and is very inexpensive.

That said Tamiya's 1/72 zero family including the a6m2, is heads and shoulders above Hasegawa and usually for under $20-25 in the US. Nice wheel wells, great cockpit detail, and 3 piece canopy. I havent built one yet but it looks amazing in the box. Its far better than many zero kits in the larger scales.