Heart Gold and Soul Silver are remakes of Silver and Gold, so that should please nostalgic people.
They apparently look nothing like the originals, with recycled buildings and things from the other DS pokemon games. Just what I heard though, I don't buy games I can't read. Also the first gen region revisits are a joke with gym leaders being severely under leveled compared to you by the time you beat the elite four to get to them.
Red/Blue/Yellow = Awesome
Silver/Gold = My favorites of the series
Crystal = Getting a bit complicated
Ruby/Sapphire/Emerald = Could not beat these games for the life of me, half the map was flooded and they simply weren't fun
Diamond/Pearl = Better then the GBA ones, although that isn't saying much. I managed to beat these ones
Platium = It's the same game as D/P except a bit more, or something. I haven't beaten it yet, I keep getting tired of it.
Honestly I'd like it if they went back to basics. I mean sure, maybe someone likes making their thing pretty or entering them in beauty pageants or running around symmetrical tunnels digging for stuff items you'd never ever use but still, all these side things are just broken unless they can perfect them, and while they're trying to implement these things the core game itself suffers from a lack of attention. Silver/Gold and the first gen games did not have a bunch of irrelevant side stuff, they were 100% adventure time and that's why they were the highlights for many people.