Postino Arcadia has excellent food and a great ambiance, perfect for a date or just a relaxed evening out. Everything I have eaten there has been top notch, and I would specifically recommend the cheese plate, as well as the prosciutto with brie panini.
The one downside is the completely unnecessary valet parking. While not that much money ($3), it feels like the restaurant is trying to squeeze a few more bucks out of you and is not a nice way to end the evening.