Why 1923? Because that's when Time began publishing (which means Ulysses, which came out the previous year, didn't qualify for the list). Critic Richard Lacayo explains how the books were chosen and adds:
Lists like this one have two purposes. One is to instruct. The other of course is to enrage. We're bracing ourselves for the e-mails that start out: "You moron! You pathetic bourgeoise insect! How could you have left off...(insert title here)." We say Mrs. Dalloway. You say Mrs. Bridge. We say Naked Lunch. You say Breakfast at Tiffanys. Let's call the whole thing off? Just the opposite—bring it on. Sometimes judgment is best formed under fire. But please, no e-mails about Ulysses. Rules are rules.
Managing Editor James Kelly has this to say:
I know the list will spark lots of discussions, but I hope it also sends you back to books you read with pleasure years ago as well as to books that you may not have heard of.
Absolutely. Take a look at the list and then tell us what you think. What's missing? What's on the list that shouldn't be?