The primary scientific output from an astronomical telescope is the collection of papers published in refereed journals. A telescope's productivity is measured by the number of papers published which are based upon data taken with the telescope. The scientific impact of a paper can be measured quantitatively by the number of citations that the paper receives. In this paper I will examine the productivity and impact of the CFHT, Gemini, Keck, Magellan, Subaru, UKIRT and VLT telescopes using paper and citation counts.