De Chirico was a kind of proto-Surrealist, his key work done in the early 20th century, a major influence on Max Ernst as well as on those who came after him. I'm much more drawn to his mysterious, dream-like plaza scenes ("The Red Tower" & "Mystery and Melancholy of a Street"):
than to the mannequin ("manichino") ones (though, as "The Disquieting Muses" evidences, they're not mutually exclusive categories):
I haven't delved deeply into his work (this book is the first substantial collection I've read/looked at), but I get the impression that de Chirico's paintings were characterised by a number of repeated ramifying motifs and life-long preoccupations...much is made here of his friendship with the poet Apollinaire and the way in which he was influenced by classical mythology, particularly the figures of Ulysses and Orpheus.