I can tell that my opinion isn't very popular but I don't think the hardest position to play is in the list. Unless you consider the defensive end a linebacker these days. He is often listed as outside linebacker. I know the offense gets all the ink in the paper, but really defense is the hardest and the most important. The offense knows the plays, the defense has to respond to the play. The defensive end (aka outside linebacker) has to 1) hit the tight end, 2) Contain the sweep, 3) Rush the passer, 4) Watch for screen and reverse etc...... I believe he makes the inside linebacker and DB's jobs easier if he does his job. I am a former tight end so I am not biased.
Great disscussion you all!