I go crazy with my tags. Even other people's.
My cousin's iTunes was disgusting. She had three different ayu's on her iPod: Ayumi Hamasaki, ayumi hamazaki, and 浜崎あゆみ.
I pretty much went insane and fixed her entire iTunes library until all the Japanese artists had the characters for their names. I had to delete all the double songs she had on there and change the capital letters and such.

...it was so satisfying in the end.