A sleeper is a player taken as a backup who ends up worthy of being a starter or at least far outplays the draft slot where you selected him. Below are players ranked by the current Average Draft Position (ADP) as found on MyFantasyLeague.com considering all scoring systems as a general basis. I'm assuming a league of 12 teams where most would take six wide receivers and start three of them each week. Therefore, the first 36 are drafted to be starters and the rest are considered roster backups.
Green Players are the values/sleepers I like while Red Players are the ones I do not value high enough to ever draft. If not red or green, the player is slotted pretty close to where I see him.
Average Draft positions taken from MyFantasyLeague.com using only real drafts conducted after August 25th