{Genre} - {Artist} - {Year} - {Source} - {Tracknr} - {Title}.mp3

Cool, I use exactly the same format for downloading songs with Jemplode, so that I can run a filenames-to-tags pass in Tag Studio.

A few differences, though:

1. Instead of ".mp3", did you know you can put {ext} as a filespec into Jemplode? Like this:

{Genre} - {Artist} - {Year} - {Source} - {Tracknr} - {Title}{Ext}

(Note no period.) That way you can get WAVs and WMAs and such, too.

2. When grabbing a compilation album that contains multiple artists, I do those separately and change the spec to:

{Genre} - {Source} - {Tracknr} - {Artist} - {Year} - {Title}{Ext}

... So that the files come out in track number order.

3. I do not do character replacement. I simply make sure that all of my tracks are named in such a way that they do not break Windows filename specs, and do not contain the space-dash-space sequence in anything other than the track title (since Title is the last one in the sequence, Tag Studio correctly imports the title even if it has space-dash-space). This is pretty easy to do, I just do a few searches in emplode or Jemplode looking for the usual suspects of DOS-illegal characters. Sure, it's not perfectly accurate, but it simplifies the download procedure and gets rid of any complications.