WordPress mb.thumbGallery, on the top of the media gallery short-code
“This non invasive plugin works on the standard WordPress gallery making it prettier and optionally extending its functionality. It is special in being 100% compatible with default galleries.”
Most of the WordPress image gallery plug-ins come with their own gallery builder separated from the post / page editor creating a dependency to the plug-in itself. The mb.thumbGallery WordPress plug-in uses the default WordPress Media gallery to create a smart and cleaver gallery on any post / page of your site. It is responsive and configurable; you can choose between many sliding effects and display options and, last but not least, if you uninstall or remove it all the galleries you had before will still be there, on your page (of course with the default ugly way WordPress show them 🙂 )!
You can download and test the free version from the WordPress plug-ins repository.
The plug-in has a pay version you can get from the plug-in settings pagethat add many features to the galleries letting you decide the transition effect, the speed of the transitions, the display of a dotted index and so on.
Just install and activate it and magically any gallery on your site will be beautiful!