jQuery Image Galleries
If you don't mind paying to get decent quality, it is worth looking into plugins sold on the CodeCanyon. RoyalSlider is a good example that can save you some hassle. The developer of this component clearly cares about code size, documentation quality as well as mobile support.
SlideViewer is a lightweight jQuery gallery with a very smooth animation. You can style it easily and add title to each picture just by specifying the alt attribute.
Galleria loads the images one by one from an unordered list and displays thumbnails when each image is loaded. It will create thumbnails for you if you choose so, scaled or unscaled, centered and cropped inside a fixed thumbnail box defined by CSS.
s3Slider is a jQuery slideshow system for creating smooth transitions with images.
Gallery with a nice animation, that is similar to Apple's time machine. When you click on the top image, it fades away and the next one is shown.
Present you images in stylish way. The links are unobtrusively highjacked to open the images in an inpage popup with drop shadow and border.
A simple image gallery/viewer that is fully unobtrusive, so you can still view the images when JS is disabled.
The jQuery Cycle Plugin is a lightweight slideshow plugin. It supports pause-on-hover, auto-stop, auto-fit, before/after callbacks, click triggers and many transition effects. It also supports, but does not require, the Metadata Plugin and the Easing Plugin.
Fancybox is lightbox plugin that automatically scales large images to fit in window, adds a nice drop shadow under the zoomed item, groups related items and adds navigation through them (uses preloading).
Mootools Image Galleries
A beautiful gallery with nice animation and reflections. It supports different image loading methods.
(E)2 Photo Gallery is a open source gallery designed to allow you to upload your photos to a desired folder, tell the (E)2 Photo Gallery what folder to look at and it will automatically load the images using PHP.
Imago is an Ajax Image Gallery with focus on simplicity and ease of use. Whether your photos are on flickr, smugmug or you'd like to host photos yourself, Imago can show them.
Prototype Image Galleries
Lightbox is a simple, unobtrusive script used to overlay images on the current page. It's a snap to setup and works on all modern browsers.