I absolutley love Childe Harold's Pilgrimage, by Byron. In fact, anything by Byron or Coleridge. Coleridge actually wrote Kubla Khan (my favourite poem from him) when stoned on opium, before being interrupted by the 'Man from Porlock' (in Devon), which gives rise to the old name for an unexpected visitor or interruption, The Man from Porlock. My all time favourite poem, however, is The Raven.