It seems to me that there are a number of extremely potent fighters in AH that are only marginally harder to use than the most over used types, but the people who use them get backslaps rather than rasberries for their performances. These are the aircraft that I think are in that special category of being very powerful and easy to use and yet are neglected.
Bf109F-4:
10 minutes of WEP and extremely sweet handling make this a wonderful brawling fighter with light firepower being the biggest drawback.
F4U-1/-1A/-1D:
Fast, decent climb, decent range, average firepower with great ballistics and oh, the flaps. The F4U is simply one of the best fighters in AH.
F6F-5:
Docile handling, average firepower with great ballistics, good ordnance hauling and tough as a brick.
Ki-84-Ia:
Great acceleration, reasonably fast at AH combat altitudes, decent firepower, fast roll rate, insane WEP cycle and yet more uber-flaps.
La-5FN:
It is an La-7 that is slightly slower, only has two cannon and none of the stigma.
P-38L:
The true jack-of-all-trades in AH. There is nothing this fighter isn't at least good at, if not great at. Oh, uber-flaps for the third time.
P-51B:
Like the La-5FN, this is much like its derided sister, yet carries no stigma. The P-51B is fast and has the great high speed handling of the P-51, though slightly light on firepower.
Yak-9U:
Like the Bf109F-4, a great brawler that only lacks for firepower and fuel range. No WEP to worry about.