Title says it all, I'll go first. Terry Brook's Shannara series. I first read them around age 12-13, fresh off finishing The Lord of the Rings and I was on the hunt for something to scratch my fantasy itch. I loved them, and read them as fast as the local library loaned them to me. The other day I picked up a copy of The Sword of Shannara expecting to feel nostalgic reading it again, the way I often do when I pick up an old printed friend. Nope, complete disappointment. The plot was no longer satisfying, the writing sub-par, the world a veiled rip-off of better writer's work...I didn't even bother finishing it.