I'm a big fan of Silver Mine. I have been for a long time. In fact, I would venture to say that this is my favorite sub place. Ever. I can't quite pinpoint what is so appealing about it to me. I do know that it was a dangerous decision to decide to live within a mile of this shop. The employees are super friendly, the restaurant itself is clean, the food is cheap and oh-so-good.
Personally, I recommend the Pikes Peak or Bust which is a veggie cheese sandwich. I love it and have turned into the type of person that gets the same thing every single time...yikes!
P.S...They also deliver until the wee hours of the morning and it doesn't get much better than a tasty sub when you have been out and about in Scottsdale on a Saturday night :)