Here are my top 5 plugins that I use and think are requirement for every wordpress blog and if you don’t use wordpress find something similar ! ask questions here I might be able to help you finding it!
1. All in one SEO – I love this plugin because I don’t have to work around the php code in order to make it Search Engine Friendly , it rewrites titles, keywords and much other stuff !

2. Google Analytics – I would not be able to run this website without Google Analytics because I wouldn’t knowhow many visitors i get, where do they come from, what do they click on, what is my top content, how long do they stay on website, and most important traffic statistics.

3. Google SiteMaps – I use Google SiteMaps because when Google crawls this blog, I want him to crawl exactly the way I want and what I want, yes I could do same with robots but remember that Google sometimes misses links, and by providing Google a sitemap that is rarely to be missed.

4. Adsense Menager – If you want to make money then,this is by far best plugin you want for your blog to make money online.

5. Subscribe to Comments – That plugin is also good, it is good because people can subscribe to your comments and track the post you provided on your blog, it is also good for people to return back to your website, it happens to me many times, i go to the website I post a comment I check mark that i want to be notified by this site if it gets updated, about 15 days later i get notification, sure ill click back and check whats new who, commented back and stuff don’t you ? its our nature !

So thats about it, other plugins are mostly to customize the website where we all have different layouts therefore It would be useless to tell you about them. Notice I didn’t link any of the plugins even tho i could ? Well the sites for plugins change, and also the versions it self to, so I don’t want to be blamed because I told you to download 5 year old plugin