I use the Tune-Up app.
It's a paid and a bit expensive IMO.
But it is worth it if you have tons of music files in need of tagging.
I am also using tuneup media, sometimes its magical due to the fact that it digitally listens to songs, but it still requires investigation on many occurances because it can tag a lot of songs improperly.
I wish they had something as good as sound hound and shazaam for a computer. There are many times when tune up media will tag improperly but 95% of the time sound hound will get it, AND show the proper album the song originally appeared on.
Whats bad about tune up media is that you can get different results with the same file. If I see that it is off and I figure out the right album the song was on thru other means, I can put that info in and then
sometimes it will come back with the original album the song was on. Tuneup media works pretty good, but it still takes effort just to make sure it's right on many occasions especially that it finds the right album art and the quality of what it finds. Too often it comes back with various artist cd's for stuff that was on a full length album by the original artist.
My time consuming workflow for labeling right now is iphone for soundhound, mac, with itunes library open, safari open for internet artwork and investigation and another itunes store window open to see if I can get stuff out of there and search in the itunes store when need be. IT TOTALLY BLOWS. They really really need to have something as good as sound hound for the mac.
If iTunes could listen, label, correctly tag files, and download the artwork, i would lick Jobs' boots REPEATEDLY!!! and swear to never use anything else for music ever again despite so many of its shortcomings.
I really wish Winamp worked on a mac. I love it. It also uses gracenote's database and it can autotag songs with the push of a button and show you the artwork and the program is FREE and very very good.