I have read Lenin's Tomb and A People's Tragedy, but would like something that covers the entire history of that country's existence. Thanks in advance!
Ronald Grigor Suny's The Soviet Experiment is the best overview. It is frequently assigned as a textbook in Soviet history classes, but is much more readable than a textbook. Otherwise, there are plenty of great books, but most cover a specific period or theme (destalinization, the Great Terror, the Civil War, etc) since the entire Soviet period is quite long and diverse.