I'm a big fan of Illamasqua's Intense lipglosses. They're wonderfully pigmented, and comfortable to wear, and for glosses, they have great staying power.
Hermetic is a deep burgundy red with a metallic finish, and it is absolutely stunning, especially when it catches the light, and you get that metallic red shine.
Like most darker lip glosses, it can be quite difficult to get the colour to look even. Below, I've layered the gloss over a black lipstick (Illamasqua Pristine). This turns the lips a very deep cherry red, and makes it apply far more evenly. I'm sure you could also layer it over a red lipstick for a brighter colour, but this is my favourite way to wear it.
Overall I love the colour and the formula. But dark glosses just don't seem practical for me. The slightest bit of wind and my hair is on my lips, dragging lipgloss over my cheeks! But if you are a lover of dark glosses, this is definitely one you need in your collection!