And they may just make them since they've already done it with the new FireRed and LeafGreen versions. ^_^ I hope so!
(This belongs in the Pokemon Games section, too. *moves*)
Anyway, hmm... Tough choice. I really love them all. They're each unique with different features that make them interesting, so it's hard to choose. I guess that I'd pick the Gold/Silver/Crystal versions because not only were they really long, but they also had a lot of neat things in them, such as the phone and night/day/real clock feature. Even though the newer games are really fun, they've left out of lot of things in them that made the older versions more fun to play.
I've been playing LeafGreen a lot too, and it's very fun! ^_^ I love the Kanto region.