Over the past year? Probably Vampire Survivors.
As of late? Doom (the 2016 reboot).
Of all time? I'm actually not sure, especially if you include my pre-internet / pre-always-being-spied-on-and-tracked history. But probably it would be one of the Street Fighter 2 iterations.
I don't think I've even played 450 hours total of games in the past 25+ years, though. So, I'm probably a bit of an outlier around here.