Ah, so youre not counting mmo's?
No. MMOs are designed for longeivity because that's how they make money. Also, MMOs for the most part are games that you can nibble at content over time. The stories tend to be skin deep and only exist as a way of herding you onto the next rung of the leveling simulator.
As a kid I didn't have access to many games, so I tended to play fewer games for much longer duration. As an adult, I have the ability to buy more games than I possibly have time to complete. By choosing shorter titles, I can play a wider variety. Admittedly though, I know I'm missing out.