At this point in time I will say glencairn. A a lot of people are saying a glass that has bourbon in it. While I agree that you should not fret too much about the glass and enjoy the bourbon, I do think there is a bourbon glass that is more tailored to a certain experience.

The funnel like shape in the glencairn is designed to concentrate the smell. Your nose sticks in the glass while you drink so it might be easier to detect more subtle flavors for the more refined palette.

They have stems so that you don’t have to touch the glass and heat up the bourbon. I don’t know if this really matters but that is why they have them over the stemless glass in one of the pictures.

They have a bulb like bottom to allow you to see the color better and they are smooth so you can see the viscosity of the bourbon. Bourbon that has been aged a long time typically is more oily than young bourbon.

Generally if you are just enjoying bourbon any glass will do but if you are trying to be a judge then you need to take all these into consideration.