So far, I'd say the Seafire IIC. A great turn fighter, efficient armament, handle's well at high speeds, and carrier-based, saving me some fuel for a good duration(depending on fuel burn rate.).
Followed by the A6M2, though an all great low-turn fighter, it stresses easily at high speeds from the light armor it carries, and easily flammable. Also carrier-based.
Then the P40B. It may not hit hard or be a great turn fighter, but it can do well if you treat her right.
La5. Good in terms of speed and armament, but it easily gathers too much speed when in turn fights and have to use my flaps.