[Aerkuld]

They won't make the Scotch taste any different but they will make it easier to warm the Scotch in your hand in the way you would with a Cognac.

Once you have done that the shape of the glass will allow the aroma to collect better for you to appreciate.

There is not much to choose between the different shapes in my opinion, but a nice tulip-shaped glass or even a cognac snifter will allow you to enjoy the whole experience and not just the drinking.

Of course, if you're just interested in the drinking then it doesn't matter at all.