I use
ID3-TagIT, which can transfer filename to ID3 tags.
There's a tiny bit of a learning curve, but it works GREAT!
For example, if I have a couple MP3 files named "03-The Colons - Large Stinkydump.mp3", and "11-Remora and the Sharks - Bodysurfer Biting.mp3", then I can just highlight them, tell the program to create ID3 tags based on <K>-<A> - <T> (track number, hyphen, artist, space, hyphen, space, title) and it will do it automatically.
Yeah, that line above was confusing... but just download it! I also hear
The Godfather is good.