FreeFileViewer allows you to view over 200 different image, document, sound, and video formats.
It is a user-friendly app that is geared for making viewing file formats a breeze. FreeFileViewer lets you easily display Adobe PDF files and Microsoft Office documents without the need for Adobe Reader, or Microsoft Office, and PSD files without requiring Adobe Photoshop. FreeFileViewer is intended to be an all-in-one file viewer product eliminating the need for other, sometimes pricey, third-party apps for it to function. It is sizable and provides auto-sensing of file attributes but doesn't support drag n' drop.
To begin using FreeFileViewer, download and run it; you will be able to start viewing your desired files immediately. We found it quite easy to use, and there was little to no lag in loading the different media formats we tested.
FreeFileViewer supports the following (and more):
DAT - Data file, i.e., winmail.dat files
DOC - Microsoft Word 97-2003 document
DOCX - Microsoft Word 2007+ document
FLV - Flash video file
GIF - Graphics Interchange Format image
JPG - JPEG image
MP3 - MPEG 3 music file
MP4 - MPEG 4 video file
PDF - Adobe PDF document
PSD - Photoshop Document
TXT - Text file
XLS - Microsoft Excel spreadsheet
XLSX - Microsoft Excel 2007+ spreadsheet
And many more
For a complete list of supported formats, check the author's page.
It does ask to allow Unknown File Handler (from File.org) during installation, but you can opt-out as it is not required for the over 200 supported file formats that are included by default.