Shenmue
A great technical masterpiece from Yu Suzuki for the Dreamcast that encorporates many gametypes like Fighting, Adventure and Role-Playing, to form it's own genre entitled "FREE" (Full Reactive Eyes Entertainment). Contains one of the most explicitly detailed and interactive worlds ever created in a videogame. Every NPC and supporting character lives and breathes day to night with their own profession like in the real world. All characters/NPCs in-game are fully voiced. "Magic Weather System" for realistic generated weather efffects for each hour or day as the game passes by. The term "Quick Time Event" was first coined by this game. Known to be the most expensive videogame series created at the time, costing "$70 Million" and almost bankrupted SEGA. The series is still not complete, with die-hard fans craving for a Shenmue III!
Ryū ga Gotoku / Yakuza
A kind of spiritual successor (And more successful!) to the Shenmue games due to the very similar gameplay mechanics (Fighting, Adventure, RPG rolled into one) and heavy attention to detail for a living and breathing videogame world full of interactivity. Interesting story to enter into the near-realistic portrayal of the modern underworld life of Japan.