I find that, the more Discworld books I read, the more options I have for giving a person a really catchy “here’s the best way to start you off with this series” choice, as it’s tailored to my impressions of them. With one of my friends, the choice was Lords and Ladies, and with another, it was Night Watch. I just recently finished Equal Rites for the first time, and I would definitely recommend that as a second or third book for someone who likes the Witches novels. Alas, my favorite that I chose was Monstrous Regiment, which is closely followed by/tied with Night Watch and Lords and Ladies.
Multiple choice would have been nice, because that way I could have voted for Soul Music as well as Night Watch.
I’m surprised at the number of Small God’s votes. I had only read it recently, and although I found it to be very good I didn’t think it was at the very top.
Hooray! Hooray! Callo! Calay! Unseen Academicals came today!
Why am I talking to you people? There’s new Pratchett to read!
Wait, there’s a new book out? Why wasn’t I told?
Also, someone voted for Eric?
This. After waffling over Reaper Man and Small Gods. Ooo, and Night Watch. And Monstrous Regiment. And the Tiffany Aching books. And…
You mean you didn’t get the memo?
There’s another book in the works. Another Tiffany Aching book, I Shall Wear Midnight
Painful decision between Night Watch and Wee Free Men, but I think that Night Watch is the one I am most likely to pick up and reread (and I must listen to the soundtrack from Les Miserables while I read it).
Small Gods was the first Pratchett I read, and gets my vote for being a gateway drug.
Hm. I seem to have missed A Hat Full Of Sky and The Amazing Maurice and his Educated Rodents. That will be remedied soon.
I’m waiting for Unseen Academicals to be available as a mass-market paperback.
That will probably be as much as a year away.
It used to be quicker, but now his output has slowed, so has the transferring to paperback.
Yeah, I expected that. But then I’d have an odd hardcover amongst the paperbacks.
I have the exact same problem. I only have hardbacks of the childrens’ and special one-off books.
You can blame the other thread for leading me to this one, and finally voting. 
Now I know that there is one person in the universe besides me who thinks that Soul Music is the best Discworld book. (But probably only one.)
^I think it’s pretty decent myself. I don’t get all the music in-jokes, but Death & Family are awesome anywhere.
Thanks for reviving it. I was wondering if there was such a poll thread, or if somebody should make one.
Very tough decision but I voted for Thief of Time. I could have gone with Guards! Guards!, which was my intro to Pratchett, or the Last Hero (I really like Cohen the Barbarian) or, well, most of the rest of the books…
I wish there were more books featuring the Luggage and Cohen the Barbarian. Hey! Maybe Cohen could fight the Luggage! 
Anyone have Terry’s email address?
I voted for Small Gods, but I could just as easily have voted for Feet of Clay. For me, Feet of Clay is where Discworld stopped being spot-the-pop-culture-reference funny books and started to tackle more ambitious themes. (Mind you, Small Gods is also thematically ambitious.) All the “clay of my clay stuff” sends a chill down your spine.
And from then on, that sort of thing turns up more frequently in the series. Jingo is about war and the way we deceive ourselves about “the enemy”. The Fifth Elephant is about politics and The Truth is about journalism. Night Watch is about what happens when you put evil people in charge.
I’m surprised that Night Watch is so popular. The whole “travel back in time and meet the younger versions of characters” thing always seemed a bit like fan-service to me.
I’m not surprised The Colour of Magic and The Light Fantastic haven’t gotten any votes. Back when I started reading Pratchett, that was the Discworld series. But those are straight up parodies of the fantasy genre, as it existed back in the day. If you haven’t read Fritz Leiber or Anne McCaffrey you wouldn’t know what it’s on about. Mind you, it does add a bit of extra insight when you read Fafhrd and the Gray Mouser and you finally realize exactly where Ankh-Morpork came from.
I’m also glad that I read the series right from the beginning. Part of what makes the Discworld interesting is the way Pterry takes throw-away ideas from earlier books and develops them. You can follow the careers of many characters right the way through, even minor characters like Detritus the troll, or Mrs Cake. When you’re introduced to the character of Glod Glodson in Soul Music, you may recall a footnote from an earlier book and understand exactly why he’s called that, and that he must be from Al-Ybi. A casual aside about last desperate million to one chances morphs into something extraordinary. (And if you haven’t read the original bit in The Colour of Magic, you won’t understand why Sgt Colon and Nobby’s attempt to exploit the million-to-one chance failed in Guards Guards.)
This kind of stuff gives the Discworld a whole new dimension. It’s a series that rewards you for re-reading.
Because then you would have to include Where’s My Cow as well, and it’s all downhill from there.