Acclaimed Flop: Hugely popular, but the sales were too weak to cover development costs.
Creator Killer: A mild example, as while he still worked for Sega, Yu Suzuki's career took a serious hit and he was unable to make another game as good as Shenmue and it's heavily implied he was Kicked Upstairs.
Development Hell: After failing to make its release on the Sega Saturn due to a really difficult development on the project, which itself was started in 1996, Shenmue saw the light of day through the Sega Dreamcast in December 1999. A new installment on the series that would move the story on has been in this "pending state" for more than 10 years...
Doing It for the Art: The first game is rumored to be one of the most expensive games ever produced (roughly $70,000,000 in 1999 currency). But there's no way anyone could say it was wasted. Pushing the limits of the Dreamcast's technology to create unbelievable levels (at the time) of facial mapping and reactive AI that adhered to personal schedules for every NPC you see. Loads of tiny details like being able to open desk drawers each with their own unique texture maps and a very accurate (at the time) recreation of Yokosuka, Japan. They even went so far as to gather accurate weather pattern data for the region in the late-1986/early-1987 period over which the game takes place and integrate it (the game has its own weather pattern that it generates but upon beating the game once, you can use the period-accurate meteorological data for Yokosuka on a repeat playthrough).
No Export for You: The second one was never released on Dreamcast in North America. The Xbox release was a year later. Many die hard fans imported even though it was expensive and required a special disc that could cancel regional lockout. It was still cheaper than buying an Xbox which had just been released.
Shout-Out: German punk band "Schrottgrenze" wrote the song "Nozomis Lieder" (from the lyrics it's clear Nozomi Harasaki is meant).