Red/Blue/Green/Yellow (Generation I): 26%
Gold/Silver/Crystal (Generation II): 21%
I honestly can't choose between any of them.: 19%
Ruby/Sapphire/Emerald (Generation III): 14%
None; I don't like them.: 10%
Diamond/Pearl/Platinum (Generation IV): 5%
Black/White (Generation V): 5%

566 total votes

Lot less voters, no surprise.
Lots of people loved the originals the best, good old nostalgia.
Much as I nostalgia for the old ones too, B/W took it to a neat different direction (if only a small departure in its plot and mechanics).