TITLE: Undergraduate Introduction to Modular Forms
QUESTION [7 upvotes]: What are the best introductory texts (or lecture notes) on modular forms aimed at an advanced undergraduate audience (for a student with a course in complex analysis and two courses in algebra and analysis each)?

REPLY [5 votes]: An extremely good textbook is, in my opinion, "A first course in modular forms" by F.Diamond & J.Shurman