If you are looking for a complete digitized "piece" of literature or a reference book, the Internet Archive hosts several comprehensive Spanish-English dictionaries.
For developers or those needing raw dictionary data for software like StarDict or Aard2, the repository on GitHub is a primary source. Download Spanish English zip
Historical and comprehensive pieces like Appleton's New Spanish-English Dictionary are available as complete digital downloads on Archive.org . Quick Vocabulary Reference If you are looking for a complete digitized
The full parallel corpus is spread across multiple ZIP files. You must download all files from the DGT-Translation Memory page to get the complete set. Download Spanish English zip
The European Commission's Joint Research Centre provides a massive collection of aligned Spanish-English sentences used in official documents.