GoodReader is the super-robust PDF reader app. Lawyers on mobile devices: you gotta check it out. GoodReader, as the name implies, lets you read documents of many different shapes and sizes: PDFs, Office files (Word, PowerPoint, Excel), hi-res images, Web archives, and even iWorks files. GoodReader has earned its accolades by the way it handles huge PDF and TXT files, manuals, large books, magazines, and renderings of 100 mb and more with great speed. In addition, GoodReader now sports PDF annotation functionality, allowing you to manipulate PDFs with notes, highlights, and typewriter functionality.
Availability: iPhone and iPad