I've read some of The Wheel of Time
and Percy Jackson and the Olympians
. The first three books of WoT are pretty solid, and from what I hear the next two or three are also good, and then the series starts to stutter and slow down until the tenth book or so. Someone more familiar with the series would be better able to describe it.
I've read the first three Percy Jackson books and I found them to be pretty solid and entertaining. It helps if you're a fan of Greek mythology. Just keep in mind that they're Young Adult novels, so they're written for that audience.