Absolutely agree on the Marie Sharps. I make special trips to a shop in Manhattan to get it.
A note on the history of this stuff: it used to be called Melinda's, and was equally hard to find. It was made by a woman in Belize named (spoiler alert) Marie Sharp, who owned a farm called Melinda's. She grew more Habaneros than she knew what to do with, and at the encouragement of a friend, developed her hot sauce. Just when it started getting popular in the U.S., her distributor screwed her over. They stole her name and packaging, which she had not trademarked. And they started buying the hot sauce from a cheaper and inferior source.
Now Melinda's is everywhere, and Marie Sharp's is hard-to-find specialty item. I encourage everyone to boycott the fake Melinda's and seek out the real deal.
Here's the full story.