Scorpion? No way. But before you start flaming me and what not, let me give my sole reason:
While his moves are creative and unique, and his fatalities are excellent, his storyline sucks. Now, in the first, and even the second MK games, his storyline was awesome. He had an aura about him that just screamed badass. However, past that his storyline was nothing but a rehash. He dies, goes to the Netherealm, and returns to kill Sub-Zero. MK:DA is the first attempt in a while to actually do something original with him. However, in the end, Scorpion just comes back, and tries to kill Quan Chi. Sounds pretty familiar to me. And it doesn't help that he's spawned so many palette swaps. He may have been the original, but that doesn't count for much when you're still just one in a bunch.
For overall best storyline, I'd say it would be tough competition between Kung Lao and Kabal. Kung's reasons for achieving this distinction are a bit more obvious, but Kabal has several small things which put him right up there. Not suprisingly, these are also the reasons which contributed so much to his success with the fans.
If Kabal has anything, he has personality. His look is completely original, yet not thrown together. it fits him perfectly. His storyline has just enough mystery to be intriguing, while avoiding the pothole of confusion so many mysterious characters leave(Reiko). Not only that, but Tobias included some excellent background on him. Not boring, detailed stuff, but just some things to give him depth most new characters don't achieve until their second or third game. For instance, the little tidbit that he was part of the Black Dragon in the past offered nothing extra to his role in the overall MK3 plot, but it gave us a little more knowledge of who he is. It's those little, redundant pieces of information that flesh a character out and make him interesing.
