Overpowering a character.

You won't believe how much this detracts from the plot. Giving Naruto a bloodline limit, a magic super scroll, a pact with Kyuubi, allowing him to absorb Kyuubi, or just making him too damned powerful is just a stupid quick fix to the fact that you can't write a fanfiction involving wit and cunning, so you just make it so he can blow up people's heads with a thought. Naruto's character is built around pain, blood, sweat, and tears, not "*POP* battle done". Another thing that you people, and some Naruto characters, fail to realize is that while Sasuke is extremely powerful, he has sold his body, soul, and allegiance thrice to get there. He works as hard as he can so that he may one day defeat his brother, and he succeeds, though not with his own strength. If you are tired of characters being too powerful, or their power frowned upon, in any fandom, just talk about it.