Weirdest books

[Chapter 24]

I fairly recently finished a book by Tom Robbins (his first one, actually) titled Another Roadside Attraction. To say that this is an unusual piece of literature would be quite the understatement; indeed, it is, by far, the trippiest thing I've ever read. It includes things such as a hot dog stand/zoo (with a flea circus, some garter snakes, and a dead a tsetse fly), mushroom-collecting, a secret group of assassin Catholic monks, finding the body of Christ, and much more.
Until reading this I thought HGGTTG was a weird book, but now that looks conventional after reading Robbins' stuff.
So what are some titles of the weird, kooky stuff you've read?

[brigadista]

thats a great book - is it in print? I read it a long time ago

[Chapter 24]

I'm not sure if it is in print. I would tell you its printing date on my copy but unfortunately I lent it to someone. However I think the date that my particular book was sometime in the 80s. All I'm really sure of is that it was published in '71.

[Invincible Summer]

House of Leaves is really weird. I only read a bit of it so I don't know how it plays out, but here's a picture of a page from it:

http://upload.wikimedia.org/wikipedia/en/d/d9/HouseOfLeavesPage134.gif

[KC]

House of Leaves is really weird. I only read a bit of it so I don't know how it plays out, but here's a picture of a page from it:

House of Leaves is an incredible and profound book, as are Danielewski's other books.

[Random Precision]

I've not read The House of Leaves, but from glancing through it I believe that the technique (footnotes, etc.) was at least partially inspired by Flann O'Brien's The Third Policeman, which also uses academic-style footnotes, on a fictional philosopher named De Selby, to carry the plot forward.