#1 Steel Cage (7 times)
This is the most used match type in the history of WWE Extreme Rules. Out of nine pay-per-views under this name, three of them were main-evented by a Steel Cage match. There were three WWE Championship matches contested inside the steel cage and three title changes in this match stipulation. It truly is incredible to see how often WWE uses the steel cage at Extreme Rules. Don't be surprised if it returns on July 15th for this year's edition as well.
All of the Steel Cage matches at this event were high profile ones. Batista won the WWE Championship from Randy Orton in 2009, Edge stood tall over Chris Jericho in 2010 and John Cena survived a triple threat to win his tenth World title in 2011. Brock Lesnar ended Triple H in 2013, a spooky kid cost John Cena against Bray Wyatt in 2014 and Seth Rollins escaped with his WWE Championship against Randy Orton in 2015. Along with these big moments, The Bar managed to capture the Raw Tag Team Championships from the Hardy Boyz last year.
The only Extreme Rules events without a Steel Cage Match are 2012 and 2016, which did have a variation of it called the Asylum Match. Dean Ambrose beat Chris Jericho in a lousy match which only got good once thumbtacks were introduced. This proves that the Steel Cage is one of WWE's most trusted gimmick matches and they will always rely on it to take things to the Extreme.