I haven't been to many "new" arenas, more of the old barns. Montreal Forum, Maple Leaf Gardens, The Aud, Met Centre in Minneapolis, Le Collissee in Quebec, Calgary Saddledome and the Civic Centre in Ottawa. Copps Coliseum in Hamilton for a Memorial Cup was also considered NHL caliber at the time.
"Modern" ones are Air Canada Centre, Canadian Tire Centre, Key Bank Centre. I would rate KBC in the middle of the other two.
The one thing that stands out in the architecture for me were the escalators at the Forum. They looked like crossed hockey sticks from the outside windows. It felt like you were going into a hockey temple.