Modules that like

Modules that are buggy

These modules have annoying bugs but might still be usable.

Event
- Lots of timezone related bugs and other issues.
E-Commerce
- Shipping calculation still very immature.
Image allow users with proper permissions to upload images into Drupal. Thumbnails and additional sizes are created automatically. Images could be posted individually to the front page, included in stories or grouped in galleries.
- Corrupts images #124474. Patch available.
Image filter allows you to reference image nodes from other nodes.
- Sometimes fails to display image if token is on first line, still working out why.

TinyMCE WYSIWYG Editor.
- Removes whitespace from HTML. Patch available.
- I don't like the concept of WYSIWYG, better to use raw HTML IMHO.
- Documentation for TinyMCE compressor is wrong, must copy both tiny_mce_gzip.php and tiny_mce_gzip.js to modules/tinymce/tinymce/jscripts/tiny_mce.
- TinyMCE compressor broke some functionality, e.g. links.
- AJAX spell checker always finds spelling is correct even if it isn't.
Image pager images are shown one at a time; the user can dynamically switch among them using previous/next links.
- doesn't integrate well as far as I can tell with image.module.
LDAP authentication.
- Can't use user information in LDAP, has to copy it to Drupal first. This somewhat defeats the purpose of LDAP, even if authentication is OK.

Modules that look useful but I haven't tested yet:

Automated logout after a specified time of inactivity.
Autosave after a period of time using AJAX.
Bibliography for managing and displaying lists of scholarly publications.
Copyright for displaying copyright and license information on each node.
Diff shows all revisions like standard Drupal but it also allows pretty viewing of all added/changed/deleted words between revisions.
Dript scripting language, Dript is simpler and safer than PHP.
Google map
Google earth Provides a KML file to see visitors through the Google Earth interface by using IP of them.
Image assist allows users to upload and insert inline images into posts. It automatically generates an "add image" link under the textarea fields of your choice.
Multiple domains allows you to span one site across multiple domains. You can configure which domains to use for different parts of your site including which protocol that section uses. It can also be used to put the ecommerce or user account functionality behind https, for instance.
Secure pages A small process which will redirect the the required pages to a SSL version of the page.
Table of contents generation.