Sword of Shanara was the hardest for me to get into.... The others came pretty easy.
Favorite Book Series.... Man, that's a tough choice.... It would have to be a tie between The DragonLance Series(Pretty much all the books... I really liked the Kender Race) and The Deathgate Cycle. I read both when I was 12, but I can still remember a lot of the Places, scenarios, races, names etc. Which is pretty good for someone who can't even remember peoples names that he went to school with.