The one and only real thing I really like from the NJO is when the Yuuzhan Vong conquered Coruscant and began terraforming it into a world with actual vegetation on its surface. As someone who hates the entire notion of an entire planet becoming paved over, to see a planet like that going through an entire environmental renewel appealed to me immensely.
Of course, it all got completely reversed as soon as the godawful Legacy era began.