You like Dune and Ender's Game? Most excellent- two of my top three series. Well if you were a fan of all the books you listed, then I would highly recommend the series 'The Wheel of Time.' It is the most interesting series I have ever read. It is a series with 14 main books, the final one of which comes out this January 8th after over twenty years of waiting. The first book is titled 'The Eye of the World' and the series is done by Robert Jordon.
Well, Robert Jordon died a few years ago, but he wrote down the entirety of the series before he died and left it to the man he picked before his death to expand it and make it a book: Brian Sanderson. And he has done a FANTASTIC job.
WoT reads more like Dune- lots of details. At one point, I'll admit, he goes on for about a page and a half in one book about this girl's scarf. It can get really dull at times. But the story itself? It is the single most amazing tale I have ever seen, and based off your listed books you will likely think this is also the greatest series you've ever read.
I cannot overstate enough just how deep and interesting and amazing this universe is. Get the first two books (the first sets up stuff and the second is plain -blam!- awesome). If you don't like them, don't buy the rest. But if you liked the books you listed? I have no doubt you'll want all 14.