Jeff Erickson, professor at the University of Illinois, has published an excellent book on algorithms. He will be self-publishing this content as a paper book, but the online copy will remain available.
“I never hear anybody mentioning him but Jeff Erickson’s ‘Algorithms’ textbook  has some of the most lucid explanations I’ve come across. CLRS is often times impenetrable and for the times I didn’t like its explanation of something I turned to Jeff Erickson’s book and it hasn’t failed me yet. I’d urge anybody trying to solidify algorithms and data structures to take a look at it.” — stuxnet79