Im mixed.
The current is a big one since i wanted a portable console with a dock for ...20 years now ;)
But honest, 4->5 and 5->6 are the 2 i would take.
2d -> 3d was a revolution, concepts did not work anymore, space and tech for "high def" pictures, real audio, etc. a new dimension to work with. (theoretically you could do that prior, but realistically it started with this gen)
buuut... the generation has a definitive look. You could not just port stuff from this gen, and release it today. Not just the visuals, the gameplay too.
Gen 6? Here is, where we get to a level of fidelity that you can rerelease the game, maybe clean it up a small bit and people will for the most part be happy with it. Here is also, where the experimentation that started with gen 5 started to settle and decide which concepts work, and which did not. Games today look essentially like games from late 6. gen (from gamedesign), just refined with using the new tech to make fancier systems and such.
First person shooters with Halo, third person with RE4, action games with DMC3, ARPGs with Kingdome Hearts,... even the AC games started with Prince of Persia. GTA 3/VC/SA somehow defined the formula of modern open world games to a degree. so many genres and games that were molded by that generation.
It feels like
Gen 4 : 10 year olds
Gen 5: awkward but charming teens, experimenting, trying stuff
Gen 6: early adults that are startingtheyr first jobs and learning how stuff works
Gen 5 32 bit 2d: just kids that do theyr stuff and dont feel forced to grow up and behave how people expect them to ;)