I'lladmit it-against my mother's greatest wishes, I have binge played several games-enough that it's hard to pick a clear winner. I think I've pretty well narrowed it down to two: Mass Effect (I'm counting the whole trilogy for reasons soon to be stated) and The Elder Scrolls V: Skyrim.
From a pure total time standpoint, I have played Skyrim more than any other game, topping off (currently) at 372 hours, or 15 days and 12 hours. I've got a couple dozen characters, most created to use specifically with one of the seventy or so mods I have downloaded. Probably about 300 of those hours were devoted solely to mods-blasting deer into the air, throwing obnoxious children over city walls (I'm looking at you, Braith) and detonating world-destroying nuclear bombs.
Now, I absolutely binge-played it sometimes, but I can't say for sure that was my longest streak-that may belong to the Mass Effect Trilogy.
Last year over Labor Day weekend, I played the entire trilogy, hitting one game a day. Yes, most of my crew died in Mass Effect 2, but I defeated the Reapers and won because let's face it, it's really, really hard to not beat the one-eyed, four-legged flying purple people eaters.
That's not the point. I played it almost non-stop for an entire weekend, and that's what really counts, I guess.