Opinion: The Miz is the best mid-carder of all time

#2 He makes anyone associated with him look good

The Miz and John Morrison with the tag team titles

The Miz has been put with some random superstars. Every single one of them has benefitted at the time from working with him at the time. The Miz has been Tag Team Champions 5 times with 5 different superstars. Three of them needed the boost from Miz (John Cena was doing fine without him, Shane is Shane, regardless).

John Morrison was a great wrestler but had a mediocre level of charisma. The Dirt Sheet run with Morrison was incredibly entertaining and was a good way for The Miz to showcase his mic skills and in-ring work as an early impression.

The ShowMiz partnership (With The Big Show) was cool as Big Show was able to play monster heel while Miz built the matches and did majority of the in-ring selling. They also unified the tag titles together.

His work with Damien Mizdow served as an amazing comedic act, with Damien Sandow coincidently desperate of a new gimmick after WWE messed up his previous character by booking Sandow to unsuccessfully cash in his Money in the Bank championship match against John Cena.

His work with R-Truth together as the Awesome Truth also elevated their relevance by entering the main event scene alongside The Rock and John Cena at Survivor Series 2011.

If you think about where some of these characters are at the moment, not many are around and certainly not many are as relevant as The Miz currently is. He sits in the mid-card and moves from superstar to superstar doing great work to support the show.