A lot of "must reads" depend on your background and interest. GEB for example I would classify as a must for anyone with a computer science background, The Glory of their Times for any baseball fan, Democracy in America for anyone into American politics.
I have a solid CS background and tried once to read GEB and while very enthralling I could only get about a quarter through. I will have to try that one again. Cheers.
I stalled out after a couple of the chapters the first time I tried GEB. Let it sit for a year or two, picked it up again and got totally enthralled and just plowed through it. I think maybe you have to be in just the right mood, or at just the right place mentally, to really want to jump into GEB. But when you do... what a rush.
