I would suggest Play Winning Chess by Yasser Seirawan. Also, Chess by Laslo Polgar is good. I think as chessplayers we forget about our fundamentals because we see them as simplistic. The most brilliant combinations or plans are composed of fundamental ideas. Do not look to overcomplicate things. Look for a book that breaks down the base ideas of chess and then build up from there. There are tons of players that level off at rating plateaus because their base was only half built.