Let's face it: the visualizer is not iTunes's strong point. But on comes this little piece of open source software, GasLight, to finally give Apple's music player the visualizer that we all expect. GasLight is not only highly customizable, it's also simply beautiful (check the glow effect). We were really impressed by the range of colors, movements and shapes that it produced. Furthermore the application is simple to set up and works right inside your iTunes, syncing its movements and effects with the music you're playing.
You'll be able to adjust almost everything in terms of colors, shades, shadows, movements and transitions. GasLight also includes a useful autopilot function to let everything run by itself. One thing to look for is not running to many applications at the same time as GasLight as it can use up a bit of memory at times. Overall though, an excellent addition to your iTunes and one of the best visualizers for Mac, if not the best.
GasLight is an impressive and highly customizable visualizer for iTunes.