Thanks in no small part to my brother & sister-in-law being awesome cooks, I am thoroughly addicted to shiitake mushrooms. Some things I like to do with them:
Fry up about 4 oz with butter, add an egg, scramble, sprinkle with goat cheese. Power breakfast.
Saute them with garlic and a splash of lemon juice, top a raw spinach salad with the hot mushrooms.
Anchovy pizza with shiitake, to die for!
Saute with garlic, chop, mix with cream cheese and cooked chopped asparagus (salt & pepper to taste). Line a baking pan with saran wrap. Fill with mixture and refrigerate until set. Serve with crackers or good bread.
Here's a cool graphic on the life-cycle of the mushroom if you want to grow your own (This is bad advice, don't do this, just get them in the supermarket). Click on it to see the full sized image.