I would go with the Wheel of Time series, but only if you have a lot of time on your hands since each book is about 750 to 1000 pages and there are 13 books (plus a prequel) with the final book coming out in a year or so.
Another option is the Inheritance Cycle (Eragon, Eldest, Brisingr, and a yet to be released final book).
Also, you could try checking out these links for more books:
http://home.austarnet.com.au/petersy...sts_books.html
http://home.austarnet.com.au/petersy...oks_rank1.html