Just got DG's Ligeti, "Clear Or Cloudy" set

I got interested in Ligeti through (big surprise) many years exposure to 2001 and Kubrick. I just picked up the boxset Deutsche Grammophone has, and its great. I have barely begun to digest it. I am wondering if any /classicalmusic users have some thoughts on Ligeti. Are there other modern/contemporary composers you like along with him? Anything I should listen for?