I'd be happy to answer such a question, but I'd like to know what kind of thing you might classify as an "achievement"? The Ottomans made vast contributions to architecture, art, science, etc., they were one of the largest land-empires in history, ruling at it's height over a million square miles of land on three continents, they produced leaders that were of significant world-historical import and fostered many leading intellectuals over its nearly 600 year long reign. So, thinning it down might be difficult, but since you're comparing the Ottomans to empires that largely died out hundreds, if not thousands of years prior, it might be helpful to know what you think an "accomplishment" consists of.