Here's a random 3 dollar greige/taupe creme polish from Priceline, called Totally Taupe. I pretty much bought it for the name (and I'm easily persuaded).
Three coats for opacity, and the formula wasn't too bad. The brush was a tad stiff (and tiny), so it was a streaky mess until the third coat.
Here's to obsessively accumulating even more greige/taupe polishes!