>>23270582If you really care about muh story, go play BW. Besides that there's nothing on that game, honestly.
If not, you can try BW2. The good features of that game are PWT, Join Avenue, Habitat list, Hidden Grottos, Challenge Mode and Black Tower/White City. However, the first two (especially the second) are not fully usable since there's no online anymore. Also, no online means that you can't get Dream World pokémons on BW, can't get new C-Gear skins, can't download special battles on PWT, etc. The Challenge Mode is fine but you need to beat the game one time to actually use.
X/Y brings 3D graphics, customization, new pokémons, megas, amie, best breeding changes, got the best selection to catch pokémons on your run and even with ORAS the game are still being played online. However, it's a easy game, have a silly story and almost no post game. Also, people are expecting a 3rd version soon, so if that happens, then X/Y is going to be outclassed.
I think the better choice is X/Y because most of the good features from BW2 are not good anymore with the lack of the online aspect, but that's up to you. I tried showing both sides.