now lets be clear here, the order the dses came out are
original ds
ds lite
dsi
dsi xl
3ds
3ds is an entirely new console, it can play ds AND 3ds games and with the recent price drop would probably be the best choice
but if you only want to play pokemon black and no other game, its a toss between the ds lite and dsi xl
now the difference between the two:
dslite can pretty much only play games, but it can play ds AND gba games
dsi xl has a bunch of new feature, but nothing the 3ds doesnt have, but it does have a bigger screen, but at the same time, is the biggest of the three and is the heaviest too (so the less portable of the three)
my choice would be the 3ds, especially after the recent price drop (was 250$, now is 170$) and you can get it has an awesome bundle with legend of zelda: ocarina of time 3d or super mario 3d land
the bundles:


in conclusion: if you only want to play pokemon black and nothing else, get a dslite or dsi xl
if you plan on getting 3ds games too (and the next pokemon game) get a 3ds
/e: bunch of typo, prolly missed some too huhu
This post was edited by Doyek on Nov 26 2011 06:45am