Here is a top ten list of the WordPress plugins I use the most. There are definitely a lot more plugins I used but this is just a nice broad taste of what is good. Hope you enjoy!

1. WP Super Cache – wp-supercacheThis is a very fast caching engine. This is great for making your site load faster and making sure your visitors get static html 99% of the time. One thing to watch out for though if you are a developer or designer and working on a WP site, do not have this activate. It caches so much you won’t see the design changes to your site!
2. Gravity Forms – gravity-formsThis is in my opinion the best WP form plugin. It has enough options to build any forms you need today. Built in logic, price fields, post fields, schedule forms, multi page forms, and it keeps going. It costs 40$ for a one time use but honestly its clean, efficient and saves coding hours. Definitely worth it.
3. Widget Logicwidget-logicThis plugin is great for a WordPress site with numerous sidebars and templates. With this plugin you can assign sidebars to certain pages, archives, categories, posts. It makes things a lot easier and saves time from having to build in all those widgets into the theme.
4. Ad Rotateadrotate This is a really simple way to add and manage ads on your WordPress site. It gives you the option to show a random banner, or multiple banners, preview the ad before posting it and email reminders for when you ads are about to expire. This is by far one of the best ad plugins for WordPress
5. Nice & Clean Sliding Loginnice-clean-loginThis plugin is great for adding that extra edge to your blog. It’s a nice and clean sliding panel login that is automatically placed op top of your header ready to be used. There is also the option to add your own fields to the panel and customize as you see fit.
6. WordPress SEOwordpress-seo This is one of the best SEO plugins to date. The features include Robots Meta configuration, Canonical, Breadcrumbs, Permalink clean up, XML Sitemaps, RSS enhancements, Edit your robots.txt and .htaccess, Clean up head section, API Docs. It is very easy to use and certainly does the job if you trying to boost your site’s SEO.
7. Magic Membersmagic-membersMagic Members is a great members plugin for WordPress. Its features include Unlimited, Easy Integration with Existing or New WordPress Blogs, Flexible Membership Options, Payment Integration Modules, Control Subscription Length, Multiple Membership Levels Purchase, S3 Amazon Support, Unlimited Coupon Creation, Login Redirection, Sequential Course Delivery System, Controlled Content Access, Import & Export Users, Partial Content Display, Pay Per Post Access, Pay Per View, Entire Blog Protection, Custom Error Pages, Roles and Capabilities Support, Secure RSS Tokens, Download Manager, Guest Purchase, Simple Member Management, AutoResponder Integrations, Simple:Press Forum Integration, Automatic Expiration E-mail Reminder, Multi Language Support, Sales Report, Custom Widgets
8. UberMenuubermenuFor anyone looking for a great animated, jquery menu with widget capability then this is the one you need. Features include iPhone & iPad compatible, Fully Widgetized, Highly Customizable, Vertical and Horizontal Menus. This works out of the box and is simple to use.
9. uPricinguPricingA great plugin for listing pricing and packages. The features include Sleek slider front end and admin, Multiple Themes, Product-oriented Workflow, Easy to set up and use, Good documentation, Easy to integrate with other plugins . This is definitely a time saver and worth the couple bucks to buy it.
10. Sexy Bookmarks This is a great plugin to help your visitors share your site’s content with social networks. Very simple to use and different icons styles and layouts. Definitely a first choice for most blogs.