RazielKanos

This plguin simply adds a CSS code into your Admin Dashboard and hides most of the nagging messages telling you 
that you should activate or register other GPL 2 Plugins.
It doesn’t add any functions other than adding the CSS code, so there should be no trouble with other plugins you are using.

WP Remove Admin Register Nag

This plugin removes the reminders that you should register plugins you got by a theme for example

Comment blacklisting works well, but what if you actually want to stop someone from even reading your blog? This plugin will take care of that for you.
It uses .htaccess file modifications to deny access to your blog from particular IP addresses (Deny from) and then follows up with an ErrorDocument 403 redirect to a URL of your choice. It doesn’t hook into WordPress, which makes it a lot faster due to no database or PHP calls.

WP-BlockYou

A plugin that can be used to block or "ban" users via their IP address from viewing your blog, and then redirecting them to a URL of your ch …

WP Remove Admin Register Nag vs WP-BlockYou