memorable Npcs

Your average NPC is forgettable and blends in with the environment. Shopkeeper Bob is just another shopkeeper, or the "Jennifers" are the servants, no one stands out and any NPC can fill the roll they take on (named or not). But we all have a favorite NPC. When you think about your favorite one, you remember something about them that makes them different. As a GM, I create a lot of characters for my players to interact with, and I have had several I really enjoy. Two in particular come to mind. Let me introduce you.

You are traveling through the wintry forest. As you trudge through the snow, you are cold and getting hungry. You come to a clearing with a monastery whose people are quite friendly and inviting. The courtyard is dominated by an ancient oak tree and sitting on a low branch is a pale blue skinned elf with silvery hair. Meet Spring, the only dryad that lives openly among the people of the monastery and their guests, proving wisdom, healing, and guidance to any who listen.

Spring first met the party in another forest where she asked for their aid in stopping an evil mage from taking any more of her children. In doing so, they found out she was the spirit of the ancient oak found within the keep. Eventually, they were able to return her to the oak and in return, still aided the party by providing history and guidance for any situation.

As a young page, you come across some ancient texts. You have scoured the library to try to find understanding. After hours of study, you find yourself amid multiple piles of books and still nothing. As a last hope for clarity you turn to the one who would know best. Meet Tatra, an elder within the temple. She provides her wisdom:
         Thoughts intrude with a breath so deep,
         Find them more clearly throughout your sleep.
         Guides for the path to knowledges lost,
         Know not how steep this action does cost.

Tatra is a prophet. In asking her questions, she often provides riddles. Rarely will she speak plainly, but often causes more questions than gives answers. Those that heed her advice are better for it, they just have to decipher it first. With riddles such as this, what could go wrong?

The players in my games remember these characters for the reasons I have shown. They are unique and have their own personalities, making them stand out among the other NPCs. These are not the only two, I have several unique ones in each of my campaigns, but I felt these two provide strong examples. So, want your players to invest in a NPC? Make them memorable.