Shinji Ikari
A real sweet guy, but he's got problems. His dad, Gendou rather abandoned him during early childhood. Shinji has a really tough time being social, but he tries to open up a little to his friends at school and to Misato his new guardian.
Asuka Langley
Asuka is in no uncertain terms the bitch of the series. She has a wonderful attitude of "I am better than you, bow down to me as your goddess." Most of this stems from her mother's death which occured when Asuka was only 4 years old. She had to grow up quickly and has ever since only wanted to impress upon people and be number 1.
Rei Ayanami
Rei has no personality to speak of and we only see any amount of emotion from her three times. After Shinji saves her life she smiles. She cries just before she "dies" and she cries again later in the series. Rei is rather suicidal and values others lives much more than her own. She feels as if she has nothing to live for, and Shinji tries to prove her wrong.