The easiest to remember is: Χρόνια πολλά / Chronia Polla, which you can use also for Christmas, birthdays, name days etc.
Καλή Ανάσταση / Kali Anastasi .... is only for Easter and means: Christ is risen
alternative:
Καλο Πάσχα / Kalo Paska ...Happy Easter
Traditional I am invited always Easter and Christmas from the Families of our Deputy Mayor and I am looking forward to enjoy hours and hours their delicious home cooked food, and this nice weather now comes on top, as we can all sit outside the whole afternoons....
I wish all of you a Happy Easter and wonder if the bird on this photo from this morning sends the message: Christ has risen...

Max