http://drupal.org/node/266126

Comparing the following modules

• Lightbox2 - supports images, grouped images, slideshow images, videos and HTML content. It also supports a wide number of Drupal’s various image modules. Older versions (4.7.x and 5.x-1.x) used the prototype and script.acolu.ous libraries, but has since been re-written to take advantage of the jQuery library now included in Drupal core.
• jQuery Lightbox - a port of the Lightbox2 project which uses jQuery. It was released a few days before Lightbox2’s own jQuery version. It has fewer features and configuration options, which may be advantageous to some users.
• Thickbox - a wrapper for the jQuery “thickbox” plugin and includes image and iframed content support. It also provides integration support for Drupal’s image, imagecache and imagefield modules.
• Shadowbox - a nice module which works well and will be a very powerful tool with the addition of integration with more Drupal media modules. The only disadvantage is that it depends on 3rd party software.
• Greybox Redux - this module shows HTML content (websites) in a lightbox, but doesn’t have any support for image content.