FLAC vs MP3 vs OGG/Vorbis vs AAC

I've done a few threads like these on /g/ but I thought I'd make an article about it on here. MP3 vs FLAC vs OGG vs AAC.

What I have done here is take a song, cut out some of it (was a bit too long in my opinion, at least for the test) and then transcoded it to different formats, and then back to FLAC.
Now, this is by no means a definitive test for which format is best since a lot of variables play a role in that decision. Some formats are better at certain bitrates and different encoders are better at certain bitrates, and a lot of other factors as well.

Anyway, this is more of a self test for those interested in the quality difference between the formats AAC, MP3, FLAC and OGG. Here is one of each that I have encoded and then converted back to FLAC to hide the format (FLAC is lossless so you don't lose any quality converting from MP3 to FLAC).

Song 1
Song 2
Song 3
Song 4

The answer to which is which can be found in this RAR file.
The password is "LAwLz" without the "" and it is case sensitive. I added it to a RAR file just so that you don't accidentally open it, or if you want to send the test files to a friend or something.

The settings I used were:
AAC - CBR 320kbps (Nero 1.5.1)
OGG - VBR ~320kbps (Vorbis 2.87)
MP3 - CBR 320kbps (LAME 3.99)

The song used is called "Mikuru no Kokoro" and the original FLAC source file can be found here for those interested.

Update please read!
I noticed that the song I picked was pretty bad for this comparison. Please use these songs instead:

Song 1
Song 2
Song 3
Song 4

Again, the answers can be found in this RAR file. Password is "LAwLz" without the "". The original version of the song, in FLAC format can be found here and is called "Komm, Susser Tod (M-10 Director's Edit. Version).

Settings:
AAC - VBR ~320kbps (Nero 1.5.1)
OGG - VBR ~320kbps (Vorbis 2.87)
MP3 - CBR 320kbps (LAME 3.99)
Decided to use VBR for AAC as well, so that it's a bit more fair against Vorbis.
VBR - Various Bitrate (the bitrate is not constant throughout the song, hence the ~ before 320. In some parts it might be 290kbps and in some parts it might be 330kbps)
CBR - Constant Bitrate (the bitrate is always the same, in this case 320kbps).