I won't repeat the whole list of 100 books here, but here are the ones I've read:
"The Curious Incident of the Dog in the Night-time" (Mark Haddon)
This is a story told from the point of view of a young boy with Asperger's Syndrome. It's been suggested that I also have that, although I've never been formally diagnosed; whether I do or not, I've decided to muddle through on my own rather than seeking professional help. Still, I was interested in the premise of this book, and I read it a couple of years ago; I meant to do a review of it at the time, but never got around to it.
In brief, I thought that it was good, and it certainly kept my attention (and I didn't guess the murderer's identity before it was revealed). To some extent, my main reaction was relief - the feeling of "Well, at least I'm not that bad!" That said, by seeing the magnified version of some of my personality quirks in that story, I can understand how they may come across to other people. On a related note, although the book was all told from the boy's perspective, I thought that it did a good job of conveying other people's feelings; kind of like a jelly mould, when you can figure out what things are from the opposite shape that they leave.
"The Da Vinci Code" (Dan Brown)
Hmm, yes. I read this two years ago, after susannahf's recommendation, and I think that it works well if you treat it as a trashy novel to while away time on an aeroplane journey. Personally, I'm happy to suspend my disbelief, and enjoy it on its own merits; a similar thing applies to the film National Treasure. However, it is important to recognise that it has roughly zero basis in fact, so I do get a bit disheartened when I see people treating it as the lost secret of the ages. One of these days I'll get round to re-reading it so that I can point out the glaring flaws (e.g. his theory about the "Golden Ratio" applying to bee hives).
"Harry Potter and the Philosopher's Stone" (J. K. Rowling)
I didn't really notice this when it first came out, because it was marketed as a children's book. As time went by, the series obviously got a bit of a higher profile! By the time that the fourth book came out, I'd heard lots of people saying how good they were, but I deliberately chose to avoid them out of intellectual snobbery; I figured that if they were that popular then they couldn't be any good. However, one of my work colleagues lent me this one (the first one), so I read it to be polite, and really liked it. I then borrowed the second and third books from her, and wound up buying my own copy of the fourth one because I couldn't wait a few days for her to finish reading her copy. Looking at the series so far, I wouldn't say that the first one was the best, but it did overcome my initial resistance.
"Northern Lights" (Philip Pullman)
After I'd read the "Harry Potter" books, I came across a Usenet discussion about them (along the lines of "why are adults reading kids' books?"), and someone recommended the "His Dark Materials" trilogy as a far superior story with a similar theme. So, I picked this one up (the first in the trilogy), and I liked it, so I wound up reading all three books (and "Lyra's Oxford").
"Longitude" (Dava Sobel)
I think I'd put this book in the "popular science" genre. It's about the problems of navigation at sea in the 18th century, and the importance of being able to tell the time accurately; the main snag was that you couldn't put a clock on a sailing ship which required a pendulum, because the deck wouldn't stay level! Although this is supposed to be a true story, I've heard that it does contain various historical inaccuracies. Still, it's interesting stuff. Some of the failed attempts to claim the prize are quite entertaining (e.g. the idea that you could get a dog on the ship to bark at exactly noon each day by doing stuff on land) and it does explain the link between time and navigation (as well as the reasons for latitude not being a challenge).
"Fatherland" (Robert Harris)
I read this one a while back, although I've never re-read it. It's a bit of an odd one, in terms of the basic premise involved. Basically, it's an alternate history story, set in a world where Germany won World War II. 20 years later, plans are underway for Hitler's 75th birthday celebrations, but a detective is investigating a conspiracy, which leads him towards "The Final Solution". The thing is, if you know much about 20th century history then you'll already know the big secret that the detective is trying to uncover, so it's only a mystery for the characters rather than the reader. This left me feeling that the ending was a bit of an anti-climax, but it might work better if you don't get your hopes up in advance.
"A Brief History of Time" (Stephen Hawking)
I started reading this when I was at school, but gave up on it after about chapter 3. I made another attempt five years ago (as I was finishing my Physics A level), but didn't get much further, so I'm counting this as ½ for the purposes of scoring.
Back when the book was first published, it was hailed as being science for the layman, and it may well be more accessible than similar works (which require a PhD to understand). For that matter, if you're going to discuss the origins of the universe then that is a pretty complex subject! However, I still had trouble getting to grips with the concepts involved, i.e. I couldn't build up an understanding from basic principles. That puts me in the position of saying "Ok, Professor Hawking, I'll take your word for it that you're correct, because you're a pretty smart bloke." However, if I'm going to do that, what benefit do I actually get from reading the book at all? So, I stuck it back on the bookshelf, and I'll probably take another bash at it one day.
"Watchmen" (Alan Moore)
I've read this comic several times; I wouldn't say that it's one of my favourites (in the sense of being enjoyable to read), but it's certainly a good story, and I have one of the quotes on my website. (Paraphrased slightly: "Never compromise. Not even in the face of Armageddon.") It was originally serialised in twelve monthly installments, so if you're reading it for the first time then I advise reading one chapter per day.
"Hawksmoor" (Peter Ackroyd)
A friend of mine lent this to me at Durham; she liked it a lot, and figured that the themes involved (a devil worshipper being involved with the construction of St Paul's Cathedral) would appeal to me. I think it's technically a well-written book, but it made me a bit uncomfortable as I read it, so I didn't really like it much.
"Neuromancer" (William Gibson)
I read this in 1995, shortly after graduation. I'd heard good things about it, but I wasn't particularly impressed; it was ok, but nothing special, and I haven't re-read it since. I'm sure that it was probably very influential and groundbreaking when it first came out (talking about "cyberspace" in 1984), but nowadays I'd recommend books by Neal Stephenson or Greg Egan for a better exploration of the same topic.
"The Colour Of Magic" (Terry Pratchett)
I've read all of the Discworld books, although I started with "Mort" (the fourth in the series), and came to this one later. I think it's significant for what it started, and I've re-read it a couple of times, but I think that Pratchett improved with his later books.
"The BFG" (Roald Dahl)
I read several of Roald Dahl's books when I was young, and I'm sure this was one of them, but I don't remember anything particularly significant about it. Mind you, when I did SJA duty last year at Buckingham Palace (for the children's garden party), they had a "lifesize" model of the BFG there, and Sophie Dahl on stage as her namesake from the book.
"The Secret Diary Of Adrian Mole Aged Thirteen and Three Quarters" (Sue Townsend)
I got this one (and the sequel) when I was about 13, and I was impressed at how accurate some of the observations were (assuming that the author wasn't writing from her own experience). The TV series of the time was quite good too, but I haven't read any of the more recent books (or seen the corresponding TV series).
[Incidentally, the Telegraph were a bit sloppy with their proof-reading: they misspelt Stephen Hawking's surname as "Hawkings", and were erratic about whether or not to include the leading "The" in book titles.]
There are also a few on there that I'm vaguely meaning to read at some point:
"The God Delusion" (Richard Dawkins)
I've read a few of Dawkins' other books, and I think that he's a smart bloke who does a good job of explaining the theory of evolution, as well as suggesting areas for research. (I first read "The Blind Watchmaker" as background for my MSc project.) That said, I also think that he has a bit of a chip on his shoulder when it comes to religion. So, I'll probably read this at some point to see whether he has anything useful to say, but I doubt that I'll buy it.
"Jonathan Strange & Mr Norrell" (Susannah Clarke, Bloomsbury, 2004)
"The Time Traveler's Wife" (Audrey Niffenegger, Random House, 2003)
I know that other people have liked these, and I'm interested in the themes, so I'll probably take a look at them when I run out of other books in my stacks, but I don't have any strong feelings one way or the other. As with the Dawkins book, I'll probably borrow these from the library in the first instance, and only buy them if I particularly want to re-read them.
Coming back to the general topic of "best book" lists, there have been a couple of similar lists doing the rounds within the last year or so, which I commented on at the time:
TIME magazine's 100 best English language novels from 1923 to the present (Jan 2006)
The Science Fiction Book Club's list of the 50 most significant SF/fantasy novels from 1953-2002 (Nov 2006)
"Neuromancer" is the only book I've read which appears in all three of those lists.