It is subjective to determine the "best" space telescope as it depends on the specific scientific goals and the type of observations being made. However, some of the most advanced and successful space telescopes include: Hubble Space Telescope: Launched in 1990, Hubble has provided stunning images and groundbreaking science in a wide range of fields including astrophysics, planetary science, and cosmology. Chandra X-ray Observatory: Launched in 1999, Chandra is dedicated to observing X-rays emitted by hot, energetic sources such as black holes, galaxy clusters, and supernovae. Spitzer Space Telescope: Launched in 2003, Spitzer is a infrared telescope that has provided insights into star formation, exoplanets, and galaxy evolution. James Webb Space Telescope: Launched in 2021, the James Webb is considered the successor to the Hubble Space Telescope, and is designed to observe in the infrared range with much greater sensitivity and resolution.