1. W3 Total Cache
W3 Total Cache is an excellent wordpress plugin which improves the user experience of your site by improving your server performance and loading time, caching every aspect of your site, reducing the download times and providing transparent content delivery network (CDN) integration.
If you don’t want to use W3 Total cache, you can give Wp Super cache a try. It generates html files that are served directly by Apache without processing comparatively heavy PHP scripts. By using this plugin you will speed up your WordPress blog significantly.
3. Wp Minify
This plugin integrates the Minify engine into your WordPress blog. Once enabled, this plugin will combine and compress JS and CSS files to reduce the loading time of your web page.
With Plugin Organizer, users can organize the way the plugins are loaded when someone opens any page on your website. Users can even selectively disable plugins by page or post.
With JS and CSS Optimizer, webmasters can improve the loading time of their websites. What it does is combine several JS and CSS scripts into the single file (to minimize http requests).
Wp Database Optimizer is an excellent plugin which allows for automated scheduled database optimization. The user can specify (in days) how long in between automated optimizations.
The WP-PLS (short for Parallel Loading System) is a WordPress plugin that will enhance the loading efficiency of your Blog. Some features of PLS include automatic image optimization, parallelize HTTP connections, page speed improvement and much more.
8. Scripts Gzip
A WordPress plugin to merge and compress the CSS and JS links on the page. The plugin rewrites url() addresses in the CSS files if
necessary, leaving http:// and / links alone.
External Files Organizer is an excellent plugin which automatically combine and compress css/js files generate with wp_head() and wp_footer()