SmartLinks by AdaptiveBlue

One of my favorite plugins, SmartLinks by AdaptiveBlue automatically adds a small blue icon to the right of various links on your blog. When clicked, SmartLinks delivers relevant links from the best web sites online. Your visitors will be able to explore other places on the web right from your blog. Ease of Installation: very easy

Contact Form 7

Contact Form 7 by Takayuki Miyoshi allows you to install multiple contact forms for simple communication. I have used several contact forms for WordPress and I like the simplicity and beauty of Contact Form 7. It uses attractive AJAX when you send a message with it. Ease of Installation: very easy

Easy Gravatars

Add Gravatars to comments automatically with Easy Gravatars by Dougal Campbell, which is the easiest of the gravatar plugins to install, in my opinion. This plugin doesn’t require you to edit any theme files to use it. Ease of Instatllation: easy

flickrRSS

flickrRSS by Dave Kellam enables Flickr integration for your blog. Customization allows you to control which sets show up and what size of photos you want (e.g. square, thumbnail, small, etc.) Ease of Installation: very easy

NextGEN Gallery

This NextGENeration Photo gallery is extremely flashy but incredible for portfolios or a neat display of photos. There are many customization options and takes a few minutes to figure out but it is worth your trouble. Easy of Installation: moderate

ShareThis

ShareThis by ShareThis and Crowd Favorite lets visitors share your posts with friends. It supports e-mail and posting to social networking sites such as Facebook and Digg. Installation requires you to activate plugin and paste a snippet of code into the plugin options page. Easy of Installation: easy

Sphere Related Content

Sphere Related Content by Watershed Studio, LLC is an original plugin which automatically shows readers siilar blog posts from across the web. Plugin adds a small icon and link at the end of every post. Easy of Installation: easy

Democracy

Democracy by Andrew Sutherland is one of the better poll plugins. It uses AJAX to load data and you can add polls to pages, posts, or as a sidebar widget. A neat feature is the ability to let visitors add their own options to a poll. Ease of Installation: easy