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Strawser makes one of the best with his "Single Lady" good luck getting one though.
Josh Farley makes a mean one sider that is reasonable in price and not long of a wait. I have one in purple heart and cedar that is a jam up box call.
Dawkins makes a pretty innovative one
Ed makes a killer one sider, but his wait time is about one year out. http://www.terefenckoturkeycalls.com/1--sider.html