I highly recommend taking the distillery tour at Maker's Mark. They put a lot of care into every aspect of the production process. They even let you dip your own bottle :)
Yep, I visited it on a drive through Kentucky once. Dipped my own bottle, got the t-shirt, didn't have time for the tour though (had 2 little kids with me).
It was definitely cool to see where & how its made (and aged!).