Know what a nice and ripe fruit smells like (very aromatic) and snag it!
You will know they're special when you walk by a display and the aroma brings you in closer. As pineapples fully ripen, almost to the point of spoilage, their antioxidant levels actually increase.
Check out this link about the benefits of pineapple.
The best way to remove the, grisly core from 1/4-1/2" thick slices was to use some small cookie cutters. Keep the cores, the edges are still good to gnaw on. Yum!