I have many poetry books, 50% classics, 50% anthologies.
The anthology "Short and Sweet: 101 Very Short Poems" is the best I have read in many a year and has revived my interest in poetry. With a brilliant introduction, the selection cuts straight to the heart of the essence of poetry. I read the anthology backwards (ie: from the shortest poem {no lines, just a title} to the longest {13 lines}) to test my attention span and also get a feel for my personal preference of an optimum length of a poem (the poems longer than 8-9 lines started to feel a bit 'padded out').
If you've never read any poetry, I recommend start here with "Short & Sweet" ... or if poetry has become mundane for you, then re-start with same.