Oh dear: where to start? Yu Suzuki's 1999 magnum opus for the Dreamcast was, famously, the most expensively created game ever at the time. And miraculously - considering that it sold about three copies - it did spawn a sequel, Shenmue II. But by the time that arrived in 2001, the Dreamcast, regardless of its merits, was dead in the water, leaving such deep scars that Sega would subsequently withdraw from making consoles. Even in this day and age, you would be amazed by how good Shenmue is to play - it lets you free-roam to your heart's content, and essentially replicates everyday life in a big Japanese city (with added brawling).
The fact that Shenmue II ended on such a cliff-hanger has led entire generations of gamers to go all misty-eyed at the prospect of a third iteration, and every so often, hopes of Shenmue III are raised before, inevitably, being cruelly dashed shortly afterwards. However, you could argue that the franchise carries on in the form of Sega's best-kept secret: Yakuza. Much of the Shenmue team now works on the Yakuza titles (now up to their fourth iteration), and the Yakuza games feel nigh-identical to Shenmue in terms of gameplay.