Gen 5 is the 1st Pokemon generation that I would say truly stands the test of time from a gameplay experience. Game Freak has been releasing more & more QOL improvements with each new Generation since, but this is the 1st where everything seems to finally come together well. Great story, good challenge, and a great variety of Pokemon to choose from. Biggest improvment would have to be with moves themselves, TM's are now infinite use and many new moves were introduced to breathe new life into Pokemon old and new.