Since we all would say that the Original was the best, what was the best non-Original series? (GX, 5Ds, Zexal)
Tough choice. I'm going to have to go with 5Ds. It's the closest one of the three to the original. For children, it's a serious adventure. For old folk like me, it's goofy enough to be funny.
My least favorite has got to be Yugioh Zexal. The protagonist for that show is the dumbest main character in the franchise. Then again, the show has to re-explain some mechanics to their new audience. I felt so old when they had to explain how tribute summons worked. Also Star Driver's main character made a cameo as a main villain: