I have been using NextGEN Gallery plugin for years as a tool to handle images on this site. At the time WordPress core didn’t do a great job of image galleries and media in general. That is no longer the case. With WordPress 4.0 the media handling is fantastic. Combine that with Jetpack from Automattic, the company that runs WordPress.com, and I now have a very easy way to create a nice looking gallery directly from the WordPress post editor. Here is an example of what it can do, photos from a trip to Banff. I suggest you check it out on your site.