Tom Clancy Rainbow Six was huge!

 Although I did read the Animals of Farthing Wood was I was 10 and that was like 300 pages.  Loved it! 

Stephen King's novel The Stand is probably the longest book I've ever read.  I've read it so many times now it's falling apart.

Longest book I have read and actually enjoyed has to be Carter Beats the Devil, but it's only a baby really at 560 pgs!

Saw Gravity's Rainbow in Waterstones the other day - thought it would be like Crying Lot but it is ENORMOUS. I just don't understand how one person can have that much to say! 

I am going to read it though. One day....

Clarissa, or The History of a Young Lady by Samuel Richardson - 1500-odd pages.  I had to read it for Uni.  It was only when I got to the class that I realised everyone else had the abridged edition.  Duh ... Gold star from the tutor though

 Whew, when she finally died I felt like cheering.  Then I turned the page and found I had ten pages of her last will and testament to plough through!

'Jonathan Strange and Mr Norrell' by Susanna Clarke, which was 1024 pages, it took me awhile but I am glad I read it :)