Thoughts on NFL's toughest stadiums

Is Heinz Field the NFL's toughest stadium for opposing teams?

What about M&T Bank Stadium?

Next week we will find out where AFC North venues rate among the NFL's toughest places to play, as ESPN.com continues its Power Ranking series on the top-10 stadiums.

Both the Pittsburgh Steelers and Baltimore Ravens have been good at home for a lengthy period. The Cincinnati Bengals and Cleveland Browns haven't had much of a home-field advantage lately, but you never know. Maybe one of the Ohio teams will crack the top 10.

In the meantime, which NFL stadiums do you believe are the toughest for opponents? We'd like to hear your thoughts.