Manic Panic Electric Amethyst Hair Dye
This dye is a lovely blue based purple, and while the colour shows up beautifully, it doesn't stick and I found it to fade considerably after just one wash, even after I left it in for over four hours. It also ended up quite patchy, despite me being experienced a meticulous with hair that generally takes dye quite evenly. This is very much a pastel shade, and don't expect it to last or stain your hair very much. It is a lovely colour though, and I'd consider it pretty unique among the different ranges.
(Emailed Review from Aeryn)