I’m going to echo the sentiments of a number of posters... This is way beyond “essential”.

My wife runs a bar and she’s pretty picky about our glassware. We’ve got a ton of the stuff mentioned (and more! cordial glasses, grappa glasses, brandy snifters, champagne saucers, margarita glasses, hurricane glasses, etc. I’ve also got a small stock of beer glasses)

The “essential” glassware for our home for anything short of a formal party is as follows: white wine glasses (it’s a faux pas to serve red wine in em, but nobody actually cares as long as the glass of wine is full) and cocktail glasses (not too big, 6oz is best. less waste when a spill happens, and when your friend is on their 6th cocktail, you’ll really appreciate it).

Here is an explanation of my rationale: It is very likely you already have in your day to day circulation the equivalent of a double old fashioned and a highball glass, you can use them for their appropriate purposes. Drinking wine out of a solo cup isn’t very classy, so some sort of wine-ware is necessary, but stocking red wine glasses, white wine glasses, champagne flutes, and whatever else wine style you’d need is a waste of effort. Your drinkware should not cost more than the wine you are serving. Cocktail glasses are necessary because cocktails will get warm fast otherwise and the reason why they aren’t in an old fashioned is because you don’t want them to get watered down with ice. Also, it makes your guests feel fancy.

Unless you enjoy mules, don’t bother stocking copper mugs. If you like them, then bring your mug and some ginger ale to the party.