This kind of makes me feel.... depressed. I thought I played a lot of games but I guess not.
FF7, when I was younger without a strategy guide, had about 65 hours on it.
Dissidia for PSP has about 100 hours on it.
Mass Effect 2, after 2 playthroughs on normal and insane difficulty, add up to about 50 hours.
Metal Gear Solid 1 through 4 probably has a combined total of about 80 to 100 hours with repeated playthroughs.
Starcraft Brood War and Warcraft 3 Frozen Throne probably take the cake. Playing that online for a few hours every day after school for a few years. Don't even want to calculate it.