HGSS all the way! Even with X and Y coming out in like, a little less than a month or so, Gen II has this special place in my heart (WAT) and Gen IV kinda made that blossom (LOL. WAT). My old Gold had always been my very treasured game (before the data got corrupted and I switched to Ruby, then LeafGreen, then Emerald), but HeartGold/SoulSilver kinda ignited that old spark again. c:
Walking Pokémon, Oak and Elm, a bunch of references to everywhere, and Red?! (OMG RED) The perfect games, imo. :)
Now, only if they made a SpiritCrystal type of game... but no. Nintendo doesn't do that with remakes. *sob*