There's a couple of ways to go on this, from the completely personal. First time you see your kids on stage etc All the way up to songs which were deemed to be game changing in their significance. I'm not into Al Jolson so I can't comment on his impact in the Jazz Singer, but on the pop front the sixties seems to have all the big occasions covered - Dylan going electric, the Beatles on Ed Sullivan or Elvis from the waist down etc.
For collective anthems you will not in my opinion ever come close to beating the sound of a stadium full of Welshmen as they sing their national anthem. It brings the hairs up on the back of your neck. I am not Welsh and I have no idea what they are saying but for sheer emotion this performance cannot be beaten. Ever.