but I'll be first to suggest going to font of computer science that is TAoCP, not because you're likely to understand most of Knuth, but because it's unlikely that anyone will understand half on the first pass, so there will be something else to learn for a really long time.
If you want to design algorithms, and not just reuse an algorithm from a catalog:
"Introduction to Algorithms: A Creative Approach: Udi Manber" Is very good.
If on the other you;re interested in a an extensive srvey of algo's and data-sturcutres, see"Algorithms and theory of computation handbook", by atallah. It has 2 volumes.
There's a more recent edition available: "Algorithms and Data Structures".