Optimist, Katsuragi Misato (Evangelion)

Misato Katsuragi: If Eva and this city both operate at their full potential we might make it through this.
Ritsuko Akagi: You’re such an optimist.
Misato Katsuragi: Hey, Sometimes you need a little wishful thinking to keep on living.
Ritsuko Akagi: I see your point. It’s nice to hear a positive attitude. I’ll see you later
Misato Katsuragi: Okay., see ya.

- Misato Katsuragi from Evangelion, The Beast [1.2]

http://en.wikiquote.org/wiki/Neon_Genesis_Evangelion

Optimist, Helen Keller

No pessimest ever discovered the secret of the stars, or sailed to an unchartered land or opened a new heaven to the human spirit.

- Helen Adams Keller (1880–1968)

http://en.wikiquote.org/wiki/Helen_Keller

Spring, Susan J. Bissonette

An optimist is the human personification of spring.

- Susan J. Bissonette