Here’s Book Riot with an illustrated guide to buying the classics. Apparently their columnist thinks that people plan ahead for this sort of thing, instead of browsing our local bookstore (which is sometimes on our living room couch, in the form of Amazon) and buying whichever copy of our desired text happens to be available (all while avoiding movie tie-in covers at all costs, of course).
If you are the collector type, though, this guide is very handy. You have your paperbacks, your hardbacks, your girly Penguin clothbounds featuring flower, bird, and chandelier motifs, and your $3 thrift editions. You even have your Warhol-inspired (or so it would seem) neon monstrosities that Penguin should regret immediately if they haven’t already started.
I myself have picked up several HarperPerennial Modern Classics of late (like Brave New World and The Golden Notebook) by pure and total coincidence. I didn’t even notice they were from the same collection until the (inexplicable) olive icon started to look a little too familiar. In any case, I’m a fan so far, given the beautiful covers and humane typesetting. They also tend to include bits of supplementary material following the text, which is how I learned that Aldous Huxley wrote a book about the (supposed) demonic possession of a French convent in the 1630s. It’s called The Devils of Loudun.
Have fun wikidreaming over that one.