Androzip is a nice file viewer with the option to zip files as zip, gzip, or TAR. Very stable.
Pros:
Stable
Intuitive
Unique option for a handheld (zipping files)
Ability to send files in email
Cons:
No thumbnail viewer for images
No layout or view options
Works nicely in conjunction with ES File Explorer if you want to upload files to an FTP server.
