2 Bloopers off the top of my head:
1. In Naruto 79, right before Naruto punched Gaara to wake him up, Naruto's jacket unzipped due to the power Naruto was exerting. A couple seconds later, you see him with the jacket zipped up.
2. In DBZ, when SSJ2 Gohan fought Cell, Cell made 7 Cell Jrs. In the anime, you see Gohan kill 8 Cell Jrs.