I won't list all my preferences, but on a very basic level, I don't ever want to drink out of a Disney or flowery frosted 80s glass. I'm not five years old.
Stepping it up a little, I ideally don't want to open a glasses cupboard and be faced with a motley assortment of hideous, non-matching glasses who've clearly gone there to die, some of which were potentially pinched from a pub. Old fashioned beer glasses with handles are a definite no no. If there's one that looks like Granddad's tooth glass, I might just shed a silent tear.
I don't want a totally inappropriate size and shape of glass for my drink of choice. With regard to your guest, yes, we do do two sizes of wine glass in this house - DH drinks red and I drink white and they require different sizes for the bouquet - but that is a latter life indulgence which I wouldn't certainly wouldn't expect from everyone. A set of clean, sparkling, medium sized wine glasses will do just fine. Similarly, if I'm drinking water, I want a decent sized glass - a highball or tumbler. If I'm drinking spirits, I won't insist on separate glasses for each type, but a small attractive tumbler is the basic minimum for this category, I don't want to drink my whisky out of a beer glass.
Goodness. That is quite some demanding glass-based angst you have going on there!