Here are the most popular names in east vs. west germany in 2009:
East
(formerly German Democratic Republic)
Boys: 1. Paul, 2. Lucas / Lukas, 3. Finn / Fynn, 4. Leon, 5. Jonas, 6. Max, 7. Tim, 8. Ben, 9. Felix, 10. Luca
Girls: 1. Lilli / Lilly, 2. Leonie, 3. Hannah / Hanna, 4. Lena, 5. Lea / Leah, 6. Emma, 7. Mia, 8. Emily / Emilie, 9. Nele / Neele, 10. Anna
West
(formerly Federal Republic of Germany)
Boys: 1. Leon, 2. Jonas, 3. Lucas / Lukas, 4. Luca, 5. Maximilian, 6. Felix, 7. Luis / Louis, 8. Tim, 9. Ben, 10. Finn / Fynn
Girls: 1. Mia, 2. Hannah / Hanna, 3. Anna, 4. Leonie, 5. Lea / Leah, 6. Lena, 7. Marie, 8. Emma, 9. Emily / Emilie, 10. Lara
Babys from Berlin are not included because Berlin belonged to East and West Germany until 1990.
Reference
123.272 german birth notifications from 2009 (19 % of all babys born in 2009), compiled by Knud Bielefeld, Germany (firstnamesgermany.com / beliebte-vornamen.de)