This is my current list of plugins that I use and like using in WordPress.

GENERALLY USEFUL

• Contact Form 7 to be used with Really Simple CAPTCHA: Simple, easy contact form.
• No Self Pings: Stops WordPress from sending pings to your website (e.g. if you link internally). Old but it still works!
• Search and Replace: E.g. I changed my Twitter name from @mochimac to @saverspender, and used this plugin to change it site-wide
• Display Widgets: It lets you show or not show certain widgets anywhere you want

STATISTICS

• Jetpack by WordPress.com: I use this for the stats, mostly.
• Statpress: I also use this one for stats, gives another angle to what’s happening on your site.

RSS FEEDS

• Ozh’ Better Feed: This lets me put whatever I want in my feed’ footer
• Feedburner FeedSmith: Redirects any feed requests from WordPress to Feedburner

SCHEDULING POSTS

• WordPress Editorial Calendar: Lets me see my posts in a calendar format
• Future Calendar: I use this so when I’m writing, I have a calendar of posts beside me

SECURITY & BACKUPS

• Bad Behaviour: Denys automated spambots from accessing your website
• Hotlink Protection: Stops people from directly linking to your images or “hotlinking”
• Growmap Anti Spambot: Adds a simple checkbox “Click here to prove you are not a spammer” for human commenters
• WP-DB Manager: Super easy way to backup your blog

SEO

• All in one SEO Pack: I don’t really get SEO and how to maximize anything (too lazy to learn) but this makes it easier I think.
• Google XML Sitemaps: Creates an automatic sitemap for you so you don’t have to do it. Then you just submit it to search engines.
• Quick Page Redirect: I moved from one blog URL to another, I had to redirect all of my old posts to this one for Google Juice

SHARING YOUR POSTS

• WordPress Related Posts: Shows thumbnails of my related posts at the end of each post
• Really Simple Facebook Twitter Share buttons: Just for Facebook, Google + and Twitter. Simple and neat.
• WP-Socializer: Great for a floating bar of sharing buttons
• Shareaholic: Fabulous for having a row of Share buttons at the bottom of the page (e.g. Share the wealth!) and/or Related Posts

SPEED & SPACE

• Quick Cache: Makes your posts and pages load quicker
• Revision Control: I limit all my revisions to no more than 2 so it stops taking up unnecessary space.
• WP Smush.It: Reduces the size of the images you upload to your site for optimized loading.
• WP Widget Cache: Caches your widgets so that they don’t keep re-loading each time for visitors

COMMENTS

• @Reply: Gives Twitter-like replies when a commenter (or I!) reply to a comment — this plugin is old but it still works
• Ajax Edit Comments: Allows readers to edit their comments within a specified time frame (e.g. 20 minutes)
• Add New Default Avatar: Instead of those ugly commenter icons on WordPress, you can choose cute pictures instead
• Akismet: For spam, nothing beats this one!
• Subscribe to Comments: Lets readers subscribe to comments on a page so that they don’t have to keep checking back

MOBILE

• WP-Touch: Instant mobile interface for your readers on smartphones