What about the Encyclopaedia Britannica, Vol IV, part iii (zip)? Is that too heavy? Or is it not formatted enough?

Ooh, how about Les Mis (zip)? Or War and Peace (zip)?

I particularly like the illustrated Alice In Wonderland (zip), but it isn't very big, even with all of the pictures.

...Still going... Here's some hilarity:

The Cockaynes in Paris (zip), illustrated by Gustav Doré. ("AND OTHER ILLUSTRATIONS OF THE ENGLISH ABROAD FROM A FRENCH POINT OF VIEW")

AHA: The motherlode!

Danté's Divine Comedy, Illustrated (zip only) That's a whopping 35.4 MB compressed!