The poem that I would pick is "The Love Song of J. Alfred Prufrock" by T. S. Eliot. The poem was first published in 1915.
This poem is a great example of Modernist literature, and it provides insight into the issues of the time. In this text, J. Alfred Prufrock is concerned with the life he has had so far. He is frustrated, as he believes himself to be stuck, and unable to progress in life to the extent he would have wanted to. He is also lonely and isolated, and he laments the lack of a partner. All of these problems reflect many of the worries of modern life that became apparent in the early 20th century and that still plague our life.
The poem is written in the style known as stream of consciousness. This is a way of writing in which the thoughts of the characters are written in the way in which they appear in the characters' minds. Because of these, the thoughts are often random, convoluted or illogical.