I recently picked up Sinful Colors Mint Apple. It's a sheer turquoise duochrome color with silver flecks...or are they gold? Either way it's amazing. Beautiful color and at $1.99 (or less on sale!) at Walgreens it's quite the steal. Still sheer at one coat, solidly opaque at two coats.
It's lovely on its own but I couldn't resist dressing it up with the argyle shape on Konad plate m60 using Konad Special Polish in white. You can see there is a couple of spots (ring finger, pointer finger) where I dragged the white polish while applying the top coat but it's not noticeable from a distance.
I don't have many colors I would call a favorite, but this is definitely a new favorite of mine.