Some suggestions:

Michael K (8.06):

For a cult-ish book, I'd recommend Automated Alice by Jeff Noon.

Rob F (6.06):

House of Leaves - Mark Danielewski
Perfume - Patrick Suskind
The Mortdecai Trilogy - Kyril Bonfiglioli
The Crying of lot 49 - Thomas Pynchon

Philip M (4.04):

I saw on your website that you welcome suggestions for 'cult
books' to discuss.May I make the following list

'THE MAGUS'- John Fowles (Did this, early on - Ed.)
'THE CATCHER IN THE RYE' -J.D Salinger
'GENERATION X' -Douglas Coupland (Did Shampoo Planet - Ed.)
'BILLY LIAR' -Keith Waterhouse
'JONATHAN LIVINGSTON SEAGULL'-Richard Bach
'NEUROROMANCER'- William Gibson
'NEW YORK TRIOLOGY' Paul Auster

Chris M (1.04):

I would recommend the Dice Man by Luke Rhinehart.

Anon (3.03):

how about:
Hangover square: patrick hamilton
Ice: Anna Kavan

From Matthew (2.03)

Ridley Walker - Russell Hoban
A Scanner Darkly - Philip K Dick (more of a cult author - but this is
the beat I've read)
The Trilogy ("Malloy", "Malone Dies", "The Unnamable") - Samuel Beckett
Confessions of an English Opium Eater - Thomas De Quincy
Labyrinths - Jorge Luis Borges
Cronopios and Famas - Julio Cortezar (alternatively 'Blow Up and other
stories' - haven't read this one though).
The Unfortunates - B S Johnson
If on a winters night a traveller - Italo Calvino (Done - Ed.)
Mindswap - Robert Sheckley
The Demolished Man - Alfred Bester
Novel on Yellow Paper - Stevie Smith (Done - Ed.)
Cold Comfort Farm - Stella Gibbons
Tristram Shandy - Laurence Sterne
Flan - Stephen Tunney
Last Exit to Brooklyn - Hubert Selby Jr
Must do some work now...

From D.P. (2.03)

Here are some classic cult books that I have read which I strongly
recommend:-

Naive:Super- Erland Loe
Life After God- Douglas Coupland
Whatever- Michel Houellebecq
The Outsider- Albert Camus