This is one of my favorite images ever captured by Hubble:
Credit:NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI)
Hubble's 20th anniversary image shows a mountain of dust and gas rising in the Carina Nebula. The top of a three-light-year tall pillar of cool hydrogen is being worn away by the radiation of nearby stars, while stars within the pillar unleash jets of gas that stream from the peaks.