Twilight, Rarity, Rainbow Dash, Pinkie, Fluttershy, and Applejack all enjoy spending time with each other, and of course they enjoy a little time spent alone as well. Still, when that time spent alone is filled with the thoughts that there are other versions of yourself in a numberless amount of universes sleep and productivity doesn't always seem to be present. Thanks to Twilight they can at least find a way of talking to one another. (looking for Cover Art)
How about the mane 6 from elements of insanity