Bald eagles. 40 or 50 years ago bald eagles were about as real to me is unicorns. Now they are a common sighting in our area. Bears, too, though they are not always as welcome.
Minor things: Apples! I remember when there were just like, red (cardboard), green (so sour), and yellow (sickeningly sweet) apples. Now?! GLORIOUS. No smoking indoors in most places? Hell yes. Major things: MEDICINE. How many people do you know on their third knee? With controlled blood sugar?