Good work sneakers?

I work as an overnight stocker for Wal-Mart, so I'm constantly on my feet and moving around. At the end of my shift, my feet hurt so bad that I can barely stay standing. I'm currently working in Crocs, which help somewhat, but not totally. Even taking pain relievers rarely help. I was wondering what would be the best kind of shoe/sneaker for what I do, however not something outrageously priced.