Essie, "Go Overboard." Deep sea nautical blue/green, a very dark teal color. It looks fantastic with colored jeans. Another autumn/winter color. A few drawbacks though: first, the polish tends to separate in the jar, so you have to give it a good shake before trying to apply it. Second, it stains your nails, really badly. Third, after a few months, it got quite lumpy and goopy. (please note: darker in real life than in photo)
OPI Sonic Bloom. Looks similar to a Piggy Polish brand color that I have called "You're Blue-tiful". I love both colors, but the Piggy Polish one takes a few coats to show up this well so I might try this one out.