If you program in C# then buy this book. It's an indispensible reference with 300 code snippets of everything you never have time to look up. Snippets on things like: better ways to use collections, regular expressions, generics, delegates, exceptions, reflection, i/o, XML, and security.
MSDN is great if you already know the name of the class or function that you're interested in. But if you don't, then it can be very hard. Date formatting, for example, is under string.Format() instead of under DateTime.
C# Cookbook is goal-driven. Each topic, such as "Writing a TCP Server", "Increasing StringBuilder Performance" or "Creating a Priority Queue" is a full solution to a programming problem. It covers C# 2.0 so generics and anonymous methods are covered.
Put it beside your desk. Read ten snippets a day, and in a month you'll be a better programmer.