Fantastic taste. I read Slaughterhouse 5 when I was around 14, it's truly a great book. God Bless You, Mr Rosewater is another great one.
I personally didn't like Wheel of Time series, but that's just personal preference. It seemed that his writing was drawn out and insipid, to me.
Another fantastic series. They're definitely well within your age bracket, too. Tombs of Atuan was my favourite of the book. Apparently there's more than the trilogy out there, but I really don't want to read them - The Farthest Shore just ended it so succinctly for me, that was all I needed. It's sort of like the Matrix sequels - they seem superfluous.
Another book that I'd like to recommend is the Elric of Melnibone series, by Michael Moorcock - this book is fantastic, and really shakes up the fantasy genre by making the protagonist an antagonist of sorts. Moorcock is great, I advise his other books too.