The biggest difference between a Blogger (blogspot) and a WordPress blog is the use of custom plugins. These plugins have made WordPress blogs better in terms of functionality. Believe it or not, a lot of WordPress blog owners depend a lot on plugins. If you understand the structure and the codes, you can even make your own WordPress plugin.
How flexible! This additional piece of codes can benefit both you and your readers.
There are a lot of custom ready made WordPress plugins available to feed your needs. Here is a list of 16 great plugins which I think is really useful (however some are optional)
16 Great Plugins to Enhance Your WordPress Blog
 Adsense Manager
Control and arrange your AdSense & Referral blocks on your WordPress blog. With Widget and inline post support, configurable colours. If you monetize your blog with Google Adsense, this is a good plugin that allow you to add your Google Adsense ads using widget.
Akismet checks your comments against the Akismet web service to see if they look like spam or not. You need a WordPress.com API key to use it. You can review the spam it catches under “Comments”. By deafault, this plugin is included in every WordPress.org blogware. All you need is the WordPress.com API key to activate this feature. Signup an account in WordPress.com to obtain the API key. Without this plugin, you will receive a lot of spam comments when time pass by.
 WordPress SEO by Yoast.
This is a great plugin for your website SEO. This make it easier for you to introduce SEO (Search Engine Optimization) to your blog.
 Anarchy Media Player (AMP)
Plays mp3, flv, mov, mp4, m4v, m4a, m4b, 3gp, avi, asf and wmv hypertext links directly on your webpage. Adds buttons to the post editor for embedding swf movies including Google Video etc. I love this plugin. I found it really useful when you want to insert media content to your blog post. An essential tool for music blogs and video blogs.
This Plugin is to show a link to the last post from the commenters blog in their comment. Just activate and it’s ready. You must be grateful to your loyal readers. To show your appreciation, why not give them some link love? When your reader enable CommentLuv when they post a comment in your blog, their latest blog post link will be added at the end of his/her comment too.
 Enhanced WP-ContactForm
WP Contact Form is a drop in form for users to contact you. In the message it sends to you it gives the page the user visited before the contact page, as well as the original outside referer. It can be implemented on a page or a post. It would be easier for your readers to contact you by using this feature if you embed it in your blog. The “Contact” page of this blog is an example.
 Flexible Upload
Resize picture at upload and make thumbnail creation configurable (like WP1.5), optionally include a watermark to your uploaded images. This is casino spiele really a great plugin for those who upload their pictures directly to their host via the WordPress platform. It is really flexible as you can set the resize pixel of your image, add watermark automatically to your images, multiple uploads at once, and many more.
 Highlight Author Comment
Automatically applies a distinctive style to comments by the post’s author. This is an optional feature. It helps to differentiate the author”s comments/feedback among the readers” comments. You can customize how your comment via CSS. Here is an example of using this plugin. Notice the author”s comment is in outstanding pale green background.
 KG Archives
This is definitely a great plugin to sort out your archive. It will be really handy when you have a lot of archives made up by old posts. You can configure how your archive page look like.
 My Avatars
This plugin allows you to add avatars to WordPress comments. Yet another optional plugin, but can add some colors to your blog.
 Random Redirect
Allows you to create a link to yourblog.example.com/?random which will redirect someone to a random post on your blog, in a StumbleUpon-like fashion. When you have a lot of old posts, it is likely that your new visitors will miss out those wonderful old posts of yours. This plugin enable you to add in the code and let your readers read any random post from your archives.
 Similar Posts
Displays a list of posts similar to the current one by comparing the way they use words. This can bring your readers further to any related/similar posts.
Automatically add links on your posts to popular social bookmarking sites. These little color icons make it easy for your readers to bookmark your posts to their bookmarking sites. There is a variety of bookmarking sites icons to add on. It also make your blog more cool.
 Subscribe to Comment
Allows readers to receive notifications of new comments that are posted to an entry. This is a great feature so that your readers can receive updates on any new added comments to the post that they have subscribed.
 WP AJAX Edit Comments
Allows you and your users to edit their comments inline. Admin and editors can edit all comments. We often make mistakes. Sometimes when I leave comment in other blogs, I make some typo mistake, but I am not able to edit my comment. With this plugin, your commentors will be able to correct their mistakes made in your blog.
Adds a more advanced paging navigation to your WordPress blog. I love this plugin very much. When you have a lot of old posts, it makes it easier for your visitors or even yourself to navigate around your posts.
These are the basic great plugin that you should consider using in your WordPress blog. Feel free to try them out yourselves.