I personally enjoyed B/W more because I felt it was better paced and had a more consistenlty good soundtrack.
B2/W2 thankfully had a far less stupid ending and less pokemon psychology, but on the other hand forced me to try the stupid gimmicks it had like the movie thingy. Overall B/W was the more enjoyable experience.
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Overall I liked B2/W2 better since it had more stuff without taking away too much from what B/W had.
Even the now-obsolete Battle Subway and Pokemon Musical are still around, and just as fun (as in, for the former, "frustrating", and for the latter, "gets boring fast") as they were before. The new locations make up for a couple of now-inaccessible old ones.
The only thing I actually miss from B/W is the Cold Storage. It was such a cool place.
BW went out of it's way to be an original Pokemon game. The changes and additions made to franchise blew my mind. Unlimited TM's, the cool new Pokemon, the new region, the cool protagonist characters, It was great stuff.
BW2 at it's core is just an enormous expansion pack for BW, but still good for what it is.
I recommend getting BW first before playing BW2, but both games are great. My favorite Pokemon Generation yet.
I personally enjoyed B/W and had a more consistenlty good soundtrack.
See, this isn't fair...there are plenty of instances where a game and its sequel have overlapping sound in-game and, so, the OST of the first is better while the overall music heard in-game is better in the latter since it includes both OSTs. I agree that BW1's OST is consistently better, but that isn't to say BW2 didn't do well. They are really rocking the battle themes lately, and usually I don't care much about those.
I voted BW2 because the lack of availability of Pokemon in BW1 ruined it for me.
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