Silver FTW!
It has to be as it holds my dearest Pokemon memories and my favourite Pokemon. I loved taking my gameboy to school and sorting out trades, playing it like a stealth ninja in class because it was just too long to wait til recess/lunch breaks and being the third person in my school to get all 250! Lugia and Typhlosion my dynamic duo plus it was the last game to mark significant improvements to the pokemon formula (day/night, genders and breeding, the simple but underated blue exp bar below your health bar, the best legendaries and basically the whole package). Soul Silver will be good but it will be a diluted experience as I feel that the extra legendaries and such will change the experience, but it will have to do alot to top my favourite game of all time!
The fact it was so good is probably the main reason I was so dissapointed in RSE versions.