Bofferbrauer on 13 February 2015
On Consoles: Probably Fire Emblem: Radiant Dawn. Hyrule Warriors is approaching with high speed though.
On Handhelds: Either Tetris or Fire Emblem: The Sacred Stones
On PC: Master of Orion 2: Battle at Antares or Wizardry 8. Both are over 10 years old and still play them very much more than anything more recent. Probably way over 3000h each
