What is a good .mp3/.m4v tag editor for OS X

Easytag is available through Fink:

fink install easytag

Homebrew:

brew install easy-tag

and MacPorts:

port install easytag

Marco Schuh produced an unofficial native build, though it seems the file is currently (Feb. 2018) offline.

I'm interested in this also - I've tried a few MP3 taggers to no avail as all have so far paled in comparison to Tag&Rename which is still Windows only - I still run VirtualBox for this one application.

For .m4v files I've been using the wonderful MetaX - have used this for my entire DVD collection.

You can use the Swiss Army knife Mp3tag right within Mac OS. Take a look here:

More MP3 guessing pattern with Mp3tag in Mac OS