The richest vanilla I have tasted was bought at a crowded bazaar market in Cap Hatien, Haiti. Its beans are wild grown and collected by mountain natives. The cured beans are hard, black and deeply shriveled. The taste is the essence of exotic.
And for their extract they use rum rather than bourbon.
At least the bottle my wife brought home from her Haiti trip did. I spent some time trying to identify why it did not taste like American Vanilla.