even more so than Warner, Faulk, and Pace.
He is like 5th on all-time yards. He played well on a crummy team where other teams had only him to be concerned about. He played well on good teams and great teams when he had to share the ball with others. He was a willing blocker. He run routes hard even when he wasn't the primary target.
He was maybe the most polished receiver in NFL history with his route running. A guy that didn't necessary have the high end physical talent, but a smart, fundamental player that overachieved.
He made the 2 big plays in the playoffs. The first play in the playoffs for a touchdown and the last offensive play of the superbowl win turning a possible interception on an underthrown ball into a go ahead touchdown again by being a smart crafty WR and not tipping off the defender that the ball was coming and making an adjustment at the split second that it needed to be done.
If he had not done that, no superbowl win for the Rams.
His resume is beyond question and probably had a better overall career than the other guys already in the Hall of Fame. Go back to the 5th all time and I believe he was 2nd all time at one point behind Rice and the clutch play in the only superbowl win ever for the Rams.