To be honest, I was never the biggest fan of the original Black and White. I don't completely remember why, maybe it's because of how cheesy I found Team Plasma then, the lack of old Pokémon in the story, or the shallow post-game, but they're definitely my least favorite of the DS era games.
Black 2 and White 2, on the other hand, were nothing short of amazing for me. It has some awesome fights, very good visual backgrounds and performances (I like the brown background in caves much more than the purple one, for example), and great conveniences such as the free space, being able to move items between Pokémon, and being able to spray Repels again immediately.
And that's without saying that having such a huge regional Pokédex allows for many different potential teams. There are some epic cutscenes (Team Plasma freezing Opelucid City to name one), and Hugh shows good development as a character, unlike many other previous rivals who were either douchebags, bland or on steroids. Overall, I just love every moment of it.
However, my only real complaint with this game is that they easily could have made it much harder than the originals. A lot of the important battles had their movesets from BW dumbed down quite a bit (cough Ghetsis' Hydreigon cough), and the fact that the levels between Victory Road and the Elite Four are so close to each other doesn't feel right (perspective: as I posted on this page
, you can catch yourself half a team's worth there and use them against the Elite Four). I still find them awesome to play through, though (i've always liked battling Iris with her epic visuals, music and everything).
Despite that, they are definitely my favorite Pokémon games yet. The gigantic selection of Pokémon to choose from, so many nice conveniences and lots of places to explore make for one heck of an adventure.