Lord of the Rings is a total classic, can't go without it. Read all of them, plus The Hobbit, and now I'm reading The Silmarilion, which also rules. Next I'll get into the Unfinished Tales...
Dune is great too, really liked it, but the stuff about computers is strange. I liked the second book a lot less, and lost interest on the third one. It just got kinda dull.
The Devil's Garden is from a Brazilian author, Luis Fernando Verissimo, and it rulez. The guy is a genius - the book is a story within a story within a story within a... you get the picture.
Never read Catcher in the rye, but I'm kinda curious about it. What's all that stuff on Conspiracy Theory? What's the book about?
The Illiand and the Odissey are damn good books too, if you read a good translation of them. Don't go for the adaptations, they take away all the fun.
Another one that can't be forgotten is the Divine Comedy (or whatever it's called in english) by Dante Alighieri. The same deal as the Illiad and Odyssey apply here though - adaptations suck\, go for the full, three-book, poem version. It's scary.