I've seen a couple of bad anime, but I can't quite say one in specific.
Anyway, list tiem!
Yu-Gi-Oh 5Ds [Oh c'mon guys, I don't care about the plot, card games on motorcycles is enough]
So yeah.
If you didn't like Yugioh 5ds just because it had duels on motorcycles, that's just being really shallow. Its has a good plot, blood, a hero that can actually lose at any moment. Opinion based, its the best Yugioh yet.
And my list is currently the hellspawn of Yugioh and Beyblade, Bakugan.