defaults write com.apple.dock itunes-notifications -bool TRUE;killall Dock

Using Keyboard Maestro.

"Vox is a little and simple music player for Mac OS X with support for many file types, including FLAC, MP3, AAC, Musepack, Monkey's Audio, OGG Vorbis, Apple Lossless, AIFF, WAV, IT, MOD, XM, Games Music and many others. Includes numerous effects like Equalizer, Reverb, Time Stretch, Pitch Shift, Echo. Moreover, all supported files can be exported to AAC+, Apple Lossless, WAV and other formats with enabled effects."

They're working around the "you can't have more than one copy of iTunes running" problem with a script.

"X Lossless Decoder(XLD) is a tool for Mac OS X that is able to decode/convert/play various 'lossless' audio files. The supported audio files can be split into some tracks with cue sheet when decoding."

"By popular demand, here’s a downloadable, updated vinylTunes icon. I’ve included one version with the shadow and one without."

"Grease is a minimalist music player for Windows. Pick a directory of MP3 and/or M4A files, and Grease will play them in random order, letting you pause, skip tracks and adjust the volume from the keyboard."

9€

A free, open-source audio player for OS X, supporting a multitude of formats. Unfortunately, it's been a while since it was last updated.

"Prevents iTunes from opening when visiting iTunes Preview pages"; I'm still using NoMoreiTunes for now, though.

"NoMoreiTunes is an extension for Safari 5 which disables the script that tries to start iTunes when you visit a link to the iTunes Store. It's annoying and redundant as there is iTunes Preview for Music and Apps now."

So insanely awesome. A FUSEOFS based filesystem that all iTunes playlists available as folder in Finder.

"Fluke is a small Mac OS X utility that lets you listen to your FLAC files right within iTunes without needing to convert anything. Simply feed your FLAC’s into it and watch the magic happen!"

"I Love Stars 2.0 was a little menubar application that did just two things: 1) show you the star rating of iTunes' currently playing song and 2) let you click to set a new rating." Version 3 includes unrated song alert & keyboard shortcuts.

"Bowtie is a free application that allows you to control iTunes with shortcuts, submits your songs to Last.fm, and sports a very simple, yet very powerful, xhtml + css + javascript based theming system."