Some of the useful wordpress plugins i use. This makes my website convinient for my users. Let make your website convinient one.

1) Add to Any Share/Save/Bookmark Button:

Helps readers share, save, bookmark, and email your posts and pages using any service, such as Delicious, Digg, Facebook, Twitter, and over 100 more.

http://wordpress.org/extend/plugins/tags/addtoany

2)Akismet:

Automattic Kismet (Akismet for short) is a collaborative effort to make comment and trackback spam a non-issue and restore innocence to blogging, so you never have to worry about spam again.
http://wordpress.org/extend/plugins/akismet/

3)All in One SEO Pack:

Automatically optimizes your Wordpress blog for Search Engines (Search Engine Optimization).

http://wordpress.org/extend/plugins/all-in-one-seo-pack/

4)Global Translator:

Automatically translates a blog in 41 different languages by wrapping four different online translation engines (Google Translation Engine, Babelfish Translation Engine, FreeTranslations.com, Promt).
http://wordpress.org/extend/plugins/global-translator/

5)Yet Another Related Posts Plugin

Returns a list of the related entries based on a unique algorithm using titles, post bodies, tags, and categories.

http://wordpress.org/extend/plugins/yet-another-related-posts-plugin/