Dark Sun would be awesome, but I doubt that WOTC would change there direction now. It's Forgotten Realms with about a page worth of information on how to convert the adventure to other settings LOL.
5 out of 5 rating for Cypher System Rulebook
Another wonderfully illustrated and well organized book by Monte Cook Games. Cypher System is one of my personal favorites for ease of use and yet it has some complexity to it. If you like Numenera and the Strange you will love Cypher System.