Interesting idea. Here's an initial attempt from me:
- Generation 1: Initial WW1 fighters: E.g. Vickers F.B.5
- Generation 2: Initial 'proper' WW1 fighters with introduction of Machine gun synchronisation as key feature: E.g. Fokker E.I
- Generation 3: Later war more developed 'proper' WW1 fighters : E.g. Nieuport 11, 17, SE.5, Sopwiths, latter Fokker's etc
- Generation 4: 1920s fighters, typically biplanes. E.g. Gloster Grebe - Bristol Bulldog
- Generation 5: Early - mid 1930s fighters, typically biplanes such a Gloster Gladiators and similar.
- Generation 6: Later 1930s - early 1940s fighters. E.g. Spitfire, Bf-109 etc
- Generation 7: Later WW2 fighters, further developed, typically 2000+hp, often using cannon armament. E.g. Hellcat, Corsair, Typhoon/Tempest, FW190s, especially late war variants
After this, one gets into the era of jets.