Free: Contests & Raffles.
My snacks tend to vary but mostly right on with what everyone else has said. For any sandwich or bread type items, I pack bagels. They can get smashed and not make your sandwich explode in to a giant mess when I pull it out of a Ziploc
I just take a hoagie roll and stuff it with meat and cheese. It's going to look like it sat in the bottom of your pack eventually.