spin.js

CSS3 Loading Animation Loop

CSS3 Loading Animation

CanvasLoader Creator

Flickr Style Loading Animation Using JQuery

CSS Loading Animation Circle Style

Loading CSS spinners and bars generator for AJAX & JQuery

Ajax Style Loading Animation in CSS3 (no Images)

CSS3 loading spinners without images

Bouncy Animated Loading Animation

Sonic ? looping loaders

Simple Loading Modal

PageLoading ? jQuery plugin

Image Loader (jQuery Plugin)

Simple Content Loader

Preloadify

Source: http://designmodo.com/css3-jquery-loading-animations/