Glass, definitely. Or porcelain!
I can't think of any drink where I would prefer to drink out of plastic. I associate plastic cups with music festivals and nightclubs, not really drinking for pleasure but just to stay hydrated.
I like to drink water and other cold drinks from a glass. I like to drink hot drinks from a china item, but not pottery even though I love the look of pottery. I do not like to drink from polystyrene or cardboard take away cups. The cappuccino doesn't taste the same and I do not enjoy the experience. I do not like to drink from plastic. A hot drink from a plastic cup tastes of the plastic. Yuk. I am not a fussy person but I think it makes a big difference what you drink from.
I prefer to drink out of a glass. It seems cleaner and, I suppose, more like having a drink at home. Plastic cups seem so flimsy and I always feel as though I am going to spill the drink inside. I don't feel that way about the takeaway coffee cups, as they are much sturdier. If you are away from home, you have to drink out of whatever drinking vessel that is given to you, and I don't mind.
I've beautiful glassware and bone china which I love drinking from. I loathe drinking out of plastic, or paper, cups for that matter. I also refuse to drink from a can unless there is a straw provided but I would ask for a plastic cup if one was available to avoid drinking straight from a can.
Only glass, esp' for sparkling wine! But plastic cups are better to take on picnics & is certainly lighter in weight to carry! My daughter never had her little daughters drinking out of plastic cups, & no glasses were broken either!