Even I don't have last.fm account, I'm a freak about correct tags. I always see at album/single scans and official sites and tag as it is written there. So, for example, I can't tolerate 浜崎あゆみ - I write ayumi hamasaki (I remember that on A Song for xx it was Ayumi Hamasaki
)... All kanji etc. names are written in romaji, except for titles, when is english word(s) there - then I don't care, because I know a song.