(I would like to specify I played the Kingdom Hearts games on PS4 through the All-In-One collection)
If there's any collection I would recommend the most out of the KH games, it's definitely this one. Kingdom Hearts 1 and 2 are both fantastic games (KH2 being my favorite in the series). Admittedly I didn't spend much time with the other games. Chain of Memories I watched on YouTube, Birth by Sleep was too difficult for me, and Re:Coded just didn't interest me.