Which are your favourite ensgame books or those you are reading/studying?

Currently I´m studying "100 endgames you must know" in spanish, by Jesus de la Villa, a very good and useful book I think, though I don´t know if it´s available in english. 

I also have got "Fundamental chess endings" by Muller and Lamprecht, and "Chess endings-essential knowledge" by Averbach.

Nunn - Understanding chess endgames is a great book.

Portisch/Sarközy - 600 Endgames is older but still worth a look.

Keres - Practical Endgames isn't bad either.

Most important is working with them.

yes they do have 100 endgames you must know I studied with it before and now I'm currently working on silman,s complete endgame course.

I'm working on Dvorestky's Endgame Manual, Silman's Complete Endgame Course, and Fundamental Chess Endings, plus have Averbakh's Knight-bishop endgame book I'm working on.