It depends. My niece and nephew who are only 6 and 7 years younger just call me by my name, but all the younger ones call me Aunt Sue or Suzie (only my family gets away with Suzie). In real life, I prefer Suzanne.
My kids call their Aunts and Uncles those titles, and one Aunt who was dubbed AJ for "Aunt Jane" by a coworker. We liked it, so it stuck, with older son interchanging AJ or Aunt Jane. We have a couple of friends who have Aunt Status.
To differentiate, my step father (who has only become remotely close to us since older son was born) is called Grandpa Bill...both biological grandfathers have passed, and I didn't want to give him the grandpa title alone. He's quite alright with it, and now the younger nephews use it as well. (even his biological grandson picked that one up!)
Suzanne