Well, it depends on the font size and page size and various things like that. Some books differ SO much in that, it's crazy. But I would say like...300, 400...but of course that depends on the above things.
For me, it depends on how well-written it is. Also, typically, the shorter books are tighter. Not always true, and that's just a personal observation; but it is an observation.
*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~* A word is not the same with one writer as with another. One tears it from his guts. The other pulls it out of his overcoat pocket.
~Charles Peguy
Depends on the type of book too, kids books are shorter, adult books depends on page size and font size. Right now I'm reading a 1400 page book, and I love it.
I don't really like reading anything under 300 pages, just cuz I finish it so quickly, it just seems so short now. So I like books 500 pages, plus, but can live with shorter.