I don't find the "factual" books (Shakespeare, A Short History) as amusing as the travelogues, although they're still eminently readable. Also, Life and Times of the Thunderbolt Kid is funny, but not as funny as his earlier books, and it's much more interesting if you read it having read his other books - because it's all about him, and if you've never read any of his stuff he's just some random guy you don't have any emotional investment in. So I'd definitely advocate one of the travel books. My first Bryson was The Lost Continent, which I keep meaning to re-read; very funny, and also beautifully affecting, because it really conjures up a sense of the poignancy of small, anonymous American towns, and the way they're all being homogenised now. So you could try that. Notes from a Big Country is probably the funniest of his books - I can't think about the furniture injuries chapter without laughing even years after reading it - but IMHO it tells you a little less about America than The Lost Continent. Notes on a Small Island is funny too, although it's easiest to like if he likes your hometown (my birth city is his favourite, so that sweetened the book
). Down Under is hilarious and, like The Lost Continent, conjures up an incredibly strong sense of place and personality.
I really, really envy you for having the entire Bryson canon to discover - every book is a delight. I rationed them, but given that your folks have them all on the shelves at home I bet you get through the lot in a couple of weeks - they are just that good.
Happy reading, and let us know which one you pick xxx