Hard to say, playing the originals on VC will probably not do you much unless you're really into playing the originals. If it doesn't give you a nostalgic feel, then it could be hard to recommend it because the series HAS evolved over time. I know, hard to believe since fans have been crying that the games haven't changed >.>. The gameplay for the originals are notably different from the more recent games, there can be a sense of imbalance (those damn Psychic-type Pokemon...) and there is more commitment to grinding (not sure if you're into that). But I wouldn't be mad if you ultimately want to play these games. Despite their flaws, the original R/B/Y are among my favorite games of all time and experiencing them at least once is good to see how much the series has grown.
I'd say go with gen 4, 5 or 6 due to their ease of accessibility (though prices for gens 4 and 5 may vary). You'll probably find something to your liking going with any of these options.







