>>20323895Probably Platinum. Gen I is broken and can be VERY easy if you exploit how broken certain pokemon are, like any psychic type really. Gen II is only annoying with the level gap between you and Red, bad level grinding environment, and only has some notable hard spots (Whitney's Miltank though that's very easy if you trained a Geodude or Onix, Claire's Kingdra, etc). Emerald's battle frontier was difficult but aside from that, it was about preparing for the tough fights like Norman's Slaking (anyone else use a Dustox and spam Protect every other turn?). Gen V was an okay balance, if a bit easy. And Gen VI is notoriously easy, especially with Exp Share on.
SO yeah, Platinum.