I sat on the fence for a long time about whether or not to get any of the new OPI polishes from the Stranger Tides Collection. Eventually, I decided on three: Sparrow Me the Drama, Steady as She Rose, and Stranger Tides. I ordered them, and the day before they arrived, I saw Sinful Colors Adventure Island display in Rite Aid, and bought three: Seaweed, Star Fish, and Open Seas. I'm already a fan of Sinful Colors, and I went into a nerd-tastic trance of joy when I saw that they were duping the OPI collections in kind of an awesomely blatant way. Seriously. There might have been drool.
So, at first, I thought that Star Fish and Sparrow Me the Drama were dupes, but as you can see from the photo below, SMTD is more of a bluish pink, and SF is a bit peachy by comparison. I admit that I could not discern the difference when I was looking at my hand; it wasn't until I saw the photo that I could really tell. I think that the differences are subtle enough that it isn't necessary to own both.
I was surprised to find that I liked the formula better on SF. I found SMTD to be a bit watery. It required three coats, and SF only required two. SMTD built to opacity; however, so if you prefer the color or the brand, the wateriness isn't problematic.
Below is Star Fish on its own. I think that without the comparison nails with the OPI, that SF is an almost dupe and/or good alternative for SMTD.