I have many favorites, whether it's music (Dido or Coldplay), perfume (Mark Sassy), or the color blue; they are things that make me happy. When it comes to Graphic Design, I don't know what I would do without one particular site and set of books.
Whenever I am feeling un-inspired or just want to see some great web design I go to http://www.thefwa.com/. The FWA has a Site of the Day award, it features flash sites from all over the world. The sites range from Portfolios to the website for a brand new car or product. Some companies get really creative and interactive with their websites, like mini games or videos and customization of what you can do with their products.
My favorite series of books that feature Print Design are the All-American Ads books from Taschen, each book focuses on a decade, it features ads for various products at the time, and the movie stars that endorsed them. For me it's eye candy, I adore anything that is old and has history, and my favorite of the series is the 1920s, a lot of the ads are almost like paintings.
You can find the All-American Ad books and others at Taschen.