>>52139877BW are okay.
They lack a sufficient replacement for the Battle Frontier and generally has issues with the story taking things over too much. But as far as it goes for Story Games, N is the best of the antagonists probably.
The switch to an entirely new roster of Pokemon is the biggest boon for the game. While not all are winners, there are some very fun designs.
They're extremely linear, but the locations are at least fun. The post-game is okay, excepting for the dearth of a BF.
BW2 is a lot better.
There is an actual Battle Frontier stand in. The plot is overly present still and is significantly less interesting. However generally the game is expanded in a good way across the board. PokeStar Studios is actually more fun than I thought it'd be. As a sequel its nice to see all the old characters in slightly different positions. However, that we can't challenge our PC from the first game is disappointing.
Again, extremely linear but with some fun locations to explore. The post-game is great.
I'm generally not a fan of the swap to 3-D everything, so my view is colored by that. But I would call Gen 5 pretty solid. Probably better than any one game that came afterwards.
Its not super hardcore or challenging. The loss of following Pokemon is inexplicable as well as the loss of the full post-game in BW has no excuse.
However the ambition to use a clean slate does get respect. And the design otherwise is very well done.