>>38140377Gen 4 or maybe 5.
Gen 1 was way too simple with way too few viable Pokémon
Gen 2 was a stall metagame, and while meant that you had to play smarter and not harder, it was still pretty slow and at lower levels, boring
Gen 3 is honestly overrated IMO. Most strategies revolve around "find strong attacker, slap choice band on it." Either that or sub punch or baton pass chains.
Gen 4 Isn't perfect at all, but it introduced the physical special split and a ton of useful moves, meaning you weren't forced to teach hidden power to everything. It un-fucked all ghost and dark types. The introduction of Stealth Rocks suck tho.
Gen 5 could've been great, as the weather meta, while bad, still meant that less viable Pokémon could become usable. The power creep was awful though.
Gen 6 was completely sullied by fairies and megas.
Gen 7 had even worse power creep, what with tapus and UBs running around everywhere.