>>46424252Platinum and B2/W2, HG/SS is debatable if you don't have nostalgia for Gen II. B/W has the best characters overall, but the sequels are better in everything except plot, so it's possible to only play them if you don't care about the story.
Ranger is my favorite spin-off series, but I'd recommend starting with the 2nd, Shadows of Almia, and leave the original for when you want to play more of it, since it has more challenging capture mechanics that put off some first timers.