If we're talking any RPGs, five years. Just tabletop RPGs, eight years. Twice. I haven't actually played tabletop RPGs all that consistently. Completely skipped 2nd edition, for example.
Between finishing college and moving to SoCal (about 3 years, all told), I didn't play tabletop D&D at all. I was getting restless at the end though; I picked up a 3e PHB on launch day even with no one to play with . If I hadn't spent most of the time I was there trying to find a job somewhere else, I probably could have found a group, but I didn't. Made a point of it when I came out here, though.
I stopped playing in Year 12 (final year of high school) to concentrate more on my schoolwork. I then didn't get back into playing until at least my second year of University. I stopped again for a couple of years when I was working full-time and started my Graduate Diploma as I had too much on my plate.
I have now been playing regularly for close to 2 years again now and don't plan on stopping any time soon (apart from a couple of months break in a month from now when my first child is born )