NextGEN Gallery. WordPress Gallery Plugin NextGEN Gallery is the most popular WordPress gallery plugin, and one of the most popular WordPress plugins of all time, with over 13 million downloads.
It provides a powerful engine for uploading and managing galleries of images, with the ability to batch upload, import meta data, add/delete/rearrange/sort images, edit thumbnails, group galleries into albums, and more. It also provides two front-end display styles (slideshows and thumbnail galleries), both of which come with a wide array of options for controlling size, style, timing, transitions, controls, lightbox effects, and more.