It goes without saying that throwing Crystal into the mix is somewhat unfair since the third titles are intended to be improvement titles over the other two in most aspects.
So aside from Crystal being my favourite, beforehand it was Pokemon Silver I picked. It always strikes me as odd that I pick the opposite of the popular choice (Growlithe and Arcanine aren't all that good anyways) Ironically enough my motive for picking Silver is simply because of Lugia being the center legendary in that title (even though in the end it proved to be a moot point since you can get both legendaries in these games but you can't really fault the reasoning when it wasn't known until after playing the game) but you'd think that after the 2000 movie came out people would be going for that title.