I didn't really mind the Unova loss. As foolish as Cameron is, he is also a pretty good trainer and has raised his pokemon well. Definitely not the best person for Ash to lose against, but he's not as bad as people make out. My least favourite was against Ritchie. Squirtle simply got knocked out by a sleep powder and Charizard didn't even try to fight. So basically Pikachu was the only pokemon of Ash's to properly fight. Bit of a middle finger imo.