I almost never replay RPGs, or anything that has a story mode. I often pick up games again that are highscore base (Lumines, Project Diva f, racers, etc.). In general, my backlog increases faster than I can finish games, so replayability is not an important aspect for me. I actually prefer shorter games these days.
I do so when I've absolutely done a game, but usually some time passes in between. I replayed Portal 2 after 2 years of finishing it- it was my favorite game until I played Virtue's Last Reward. I replayed Bioshock Infinite almost as soon as I finished it, and I've gone through the first Bioshock several times.
TU FUI, EGO ERIS. What you are, I was. What I am, you will be.