Most hours spent on one game?

Probably world of Warcraft. Im at hundreds of days played (for those not familiar that would be hundreds of days if I never slept and just played straight)on my main and god only knows everything combined. I long ago stopped using /played. I just dont wanna know. It is over 10 years, but still, dont wanna know.

Longest non-mmo is Skyrim. Ive played it at least 3-4 full times (with short bursts here and there). The full play throughs are all 200+ hours each.