As far as steam games go, I have 106 hours in CS:S and 84 hours in CS:GO, followed by KSP at 57 hours. Ive only been playing KSP for a month or two though, so I suspect it will be up at number one eventually. Outside of steam, I know Ive put hundreds of hours into Minecraft since I started playing it back in Beta 1.2, and 100+ hours in a couple old playstation/playstion2 games. Ive played through Persona 3 a few times, and thats 80+ hours each time. Ive played trough Final fantasy VII many, many times. At one point I put an ungodly amount of time into Grand Turismo 4...