Pisces are very unique in the Zodiac. They are the most arty, in that they tend be imaginative and full of emotion. Pisceans are dependable and caring, and do well when surrounded by others.
However, unlike many other signs, they prefer to be dependent and subordinate. Pisces is more comfortable when they have a strong figure/role model they can look towards for guidance. Without this role model, they can become very self-pitying (borderline over dramatic) and lazy. They can also be described as over-sensitive when it comes to their emotions, appearing almost histrionic in their display.
The key to success with Pisceans compatibility lies in a combination of good role models and understanding of their feelings. When those two things are taken into account, most Zodiacs work out well with them.