Decanters are critical when entertaining. There's no whiskey bottle to compete with the heft and delicacy of even a modest decanter. The spirits in them become identified by their rich colors and by how much you've consumed rather than the sticker they arrived behind.
The only potential downside is that most crystal decanters are leaded. Leaded crystal leaches into alcohol, which means you have to decant and serve within a day or two, which is an unnecessary commitment.
That's why we tracked down Ravenscroft, whose distiller line of decanters and glasses are not only beautiful, but are also lead-free. You can leave your spirits in them for any length of time - alternately drinking from them and admiring them - without worrying about feeding lead to your guests.
This one, called the Taylor, is a classic form and has a bubble blown into the bottom, which does some pretty great stuff to the light in your whiskey.
You can also find this decanter as part of a set.