>>58541390>B2W2 has pretty good mon varity, it has some neat nooks and crannys with the sewers, early volcorona, move relearner, hidden grottos. Pretty linear overall still.
>XY has a pretty large varity of pokemon, it feels more linear but I think it's fun more for going fast than exploration, probably the only pokemon game I've replayed for the purpose of getting to the end as fast as possible, that also makes up for the small post game.
>HGSS is less linear but it suffers from weird level scaling, and a weaker encounter table, but is pretty jampacked with content and you can a lot in Kanto in particular.
>RBGYHave probably the most freedom if count glitches allowing to tackle Kanto itself in many ways, but obviously it's gen 1 so the mon varity is MUCH lower than it is now.
>SM/USUMHave a good varity but the pace of them game is so slow, I replayed it and I decided I wanted get Diglet, and the stupid stoutland guy won't let me just enter the cave to catch one, they could have just had an NPC in the cave prevent me from going to the other side or something just let me build my team, I replayed these games recently and my opinion of them shot down, they were very painful to replay I'd only suggest playing them once.