These two cams are the best ones in the for around 500 to 600 price range for compact cams. They are little higher than your price range but am sure pictures they make makes up for the price they have.
Fujifilm X10:
www.bhphotovideo.com/c/product/817840-REG/Fujifilm_16190089_X10_Digital_Camera_Black.html

Panasonic DMC Lx-7
www.bhphotovideo.com/c/search