For whisky, the Glencairn is the obvious answer as everyone else has said. I have a cut glass crystal version which was a present, I don’t know where it came from unfortunately. You can also get “tulip” glasses like miniature wine glasses which some whisky snobs- er, enthusiasts prefer because you’ve got better control over temperature.
For bourbon or something you might have on the rocks or with a mixer, I have a tumbler from here which I adore. I use it just for pop even. They do Glencairn-a-likes also. If you’re looking for something at the lower end of the budget, the Middle of Lidl often do cut glass tumblers which are perfectly serviceable at something silly like £8 for a box of 4.
I do like a nice glass or mug. We have cupboardfuls of the damn things with new ones appearing randomly every time there’s something like Easter which comes with a “gift set” but I only ever use My mug and My glass. I’d take three quarters of them to the charity shop tomorrow if I had my way. Maybe I can loosen one of the shelves and wait for an accident.