Most hours spent on one game?

I've clocked over 800 hours on L4D2. Lol. I'm not sure if I should be proud of that, though.

This would be around 600 hours for Pokemon Heart Gold (going by the total play time counter).

Battle Field. In all the series combined I probably have over a thousand hours on it.

Probably spent about 3k hours on mw2 on the 360. That game was my shit for the longest time.

That would definitely be Garry's mod or counter strike for me. Garry's mod I have 6730 hours and cs I have 3k hours. It's rough. :/

800 hours on Warframe, couldn't get enough of that game when I was younger. The amount of gift cards I converted into in-game currency was disgusting. (Runner's up include Dark Souls 3 at 700 hours and Garry's Mod at 400 hours)

Borderlands 2. I have maxed the game and still kept playing with my friends. Not sure how many hours it took from my life. Guess around 600.

Believe either Minecraft or Call of Duty Modern Warfare 2. I believe I have 2000+ hours in both of them. No exact count. Minecraft doesn't have any count from way back. Steam has, but I didn't always play on Steam, most of my hours were spent on AlterIWNet, for those who knew that.

CSGO, on all my accounts probably about 13k hours. A bit tooooo much haha

I have roughly 6k hours into oblivion. I have completed countless playthroughs and even now I will still do a vanilla playthrough