Inside Linebackers are generally the captains and leaders for the defense on NFL teams.
They are typically a team's best tackler, are relied on heavily to stop the run and team defenses are usually designed to force runners to the middle where they can make a play. If that isn't enough responsibility, they also are required to time blitzes well and drop in zone coverage.
A good inside linebacker has great strength and acceleration to the football combined with great instincts and awareness. They must instinctively shed blocks and play with a solid base, and typically are at least 6'2'' and weigh 240 pounds.
They also must play sideline to sideline—being relentless, fearlessly attacking the ball and making big plays.
Here are my Top 10 Inside Linebackers for the 2011 NFL Draft.