I’m going to answer this factually based on chart positions and certifications
1) Together Again
2) That’s The Way Love Goes
3) All For You
4) What Have You Done For Me Lately?
5 is a tossup. You have Runaway, The Best Things In Life Are Free, When I think of You, Let’s Wait Awhile, Scream, and Got Til It’s gone...
Weirdly enough, even though the RN is her most iconic era singles wise in the States, it’s her most ‘local’ out of all her signature eras. It didn’t really produce a worldwide hit, even though Escapade and LWNDWY should have easily stayed the world.