No. It's most certainly not obligatory. Pah.

You say that... but I'd be glad to have it on a 11hr flight to LA!

There are other authors I would choose in a flash over Dan bloody Brown. Or alternatively spend the 11hrs attempting to remove my face with a can opener.

Who would you recommend?

Well, if you're looking for books in an airport bookshop, they usually have a fair few Iain M. Banks sci-fi novels; he's excellent (as is his normal fiction as Iain Banks). Still on sci-fi, I'm enjoying Dan Simmons Hyperion Cantos - that's four whole books, which should easily fill up 11hrs.

I'm on a bit of a science fiction kick at the moment.

I quite enjoyed Ian M. Banks' Matter, recently. Dan Simmons, eh? Are there any audiobooks? I like audiobooks.

The briefest of brief searches tells me that there are a couple of Dan Simmons CD audiobooks, but I can't find anywhere offhand that offers them as downloads. However I'm not an audiobook person, so you may have a preferred source which is more illucidating.

Matter was good, but nowhere near his best Culture book. Try "Look to Windward", "Use of Weapons" or "Excession". They're all brilliant.

Well, of course. I look forward to more delusion-shattering, thought-provoking, US Christian Right-offending fantasy. Always enjoy his books.