What kind of sunglasses should i get and or which brand?

[Hicksville]

I have dark skin and wanna wear a pair of cool sunglasses . i am slim and have triangle face.

[Hico]

Maybe you can try some colored sunglasses to lighten your look such as white sunglasses frames.As for the frame shape, you can try a pair of square shaped sunglasses that must flatter your face shape and give your more charming look.

[Hidalgo]

You can try Leopard printed sunglasses. Anyway, I think it is hard to know what kind of sunglasses suit for just according to your description. Why don't you try on some sunglasses so that to find the best looking one? Now, most online optical shops like http://www.discountglassesdirect.com/ offer Virtual Try-On System that you can try their sunglasses with your photos online.