As for my list:
Durability
1. F4F/FM-2. The amount of damage the Wildcat can soak up and STILL keep flying (if not fighting) is insane.
2. Il-2. Needs a good concentrated burst, especially from machine guns or lighter cannon. However the fact that it's not hard to GET that good, sustained burst sort of mitigates that. Nevertheless, you're not going to bring one down by a snapshot.
3. F4U. Corsairs can take a serious beating and keep flying. Even cannon may need more than a snapshot unless you get a very luck shot that clips the tail feathers. I've also cheated quite a few guys out of kills after losing half a wing. That outer wing panel is really the Corsair's one weak spot.
4. 190s. Like the Corsair, 190s can endure a pretty healthy pounding. I will say the Dora is easier to knock out of action because of its liquid-cooled engine. I generally expect to need a good second or so burst to break off something important. Like the Il-2, though, the 190 generally isn't too hard to get that sustained shot needed to take them out.
Hard to Hit (I am NOT counting the 262 or 163)
1. A6M. The Zeke has a frustrating capability of dodging out of your sights right as you get lined up for a shot.
2. F4F/FM-2. The Wildcat's small size and good maneuverability makes her a REAL pain just to hit.
3. Spitfires. Like the Zero and F4F, the Spitfire's size and maneuverability can make her a difficult target
4. Ki-84. Ditto.
Overall
1. F4F/FM-2. Its combination of small size, maneuverability and freakishly rugged airframe makes the Wildcat IMO the toughest fighter in the game to bring down.
2. F4U. Although a big aircraft, the Corsair's maneuverability and rugged construction means she can evade a lot of what gets thrown at her, and soak up the rest. The only real weak point is the outer wing panel.
3. Ki-84. Although not as tough as the Corsair and Wildcat, the Ki-84 can still take a pounding. Her exceptional maneuverability makes her an incredibly difficult target to hit.
