Writing about sleepers in fantasy football is a tricky task because someone always swears up and down that he was tracking the guys you list before you.
So tracking sleepers is like being a hipster. It's not cool unless you picked them out first.
The reality is that sleepers are merely guys whom the world at large are undervaluing at this very moment. It happens every year, and the players involved are different every year because once a guy has a great season, everyone is all over him.
So here are a dozen players the majority are missing out on right now; you should be grabbing them before they sell out, become mainstream and aren't cool anymore.
As a general note, this is a list of players for a point-per-reception league. In other words, you get an extra point for every catch a receiver or running back makes.
But you probably haven't heard of it before. It's very underground.