Hm. Voted 5-6. I tend to start a lot of games, but persist only with a few. I might only finish 2-3 games every year.
Also, my backlog is so long that I run a few years behind, so I haven't played any of the recent titles yet (the most recent one would be D:OS EE). Big advantage is by the time I get to them, they're fully patched up and as complete as can be.
Heh, I might even go back to even older titles on a whim. I just started my umpteenth attempt at G3, for example, and G1 is also sitting on my disk waiting to be continued.