Ah, the GS generation was my all-time favorite Pokemon generation ever.
The nostalgia is staggering. One reason is at the time, no one was really expecting added Pokemon characters like we routinely do now, so I was stoked for all the new pokemon.
Also, the day and night system was a neat idea. Playing the game at night would mean playing in a night setting. It was just... cool.
And when I bought the game (Silver, to be specific), I blasted through it. DAMN it was fun.
But the best part was taking my first step into Kanto (greeted by the fat guy, of course), and playing through the original set of leaders once again. AWESOME.
You can tell that Gamefreak really put their heart and soul into the GS generation.
Now, I don't know just how great HG and SS will be (I'm waiting 'till it comes Stateside), but I'm recommending you get those instead of Platinum. Just for the sake of nostalgia