Sky is separate because it's slightly different and yeah.
Anyways, my favorite is Sky. I liked using the new starters in there (and my favorite was my first one, Vulpix) better than the old ones, and the story was pretty good. GTI was dull as far as I got, but I haven't finished it, and Red and Blue are good (except for being too difficult for me ;-, but Sky (and Time and Darkness, I guess) are better than it.
Anyways, my favorite is Sky. I liked using the new starters in there (and my favorite was my first one, Vulpix) better than the old ones, and the story was pretty good. GTI was dull as far as I got, but I haven't finished it, and Red and Blue are good (except for being too difficult for me ;-, but Sky (and Time and Darkness, I guess) are better than it.