Janis Elsts

Admin Menu Editor lets you manually edit the Dashboard menu. You can reorder the menus, show/hide specific items, change permissions, and more.
Features
<ul>
<li>Change menu titles, URLs, icons, CSS classes and so on.</li>
<li>Organize menu items via drag & drop.</li>
<li>Change menu permissions by setting the required capability or role.</li>
<li>Move a menu item to a different submenu. </li>
<li>Create custom menus that point to any part of the Dashboard or an external URL.</li>
<li>Hide/show any menu or menu item. A hidden menu is invisible to all users, including administrators.</li>
</ul>
The <a href="http://w-shadow.com/AdminMenuEditor/" rel="nofollow ugc">Pro version</a> lets you set per-role menu permissions, hide a menu from everyone except a specific user, export your admin menu, drag items between menu levels, make menus open in a new window and more. <a href="http://amedemo.com/wpdemo/demo.php" rel="nofollow ugc">Try online demo</a>.
Additional Features
Despite the name, this plugin is not limited to just editing the admin menu. You can also:
<ul>
<li>Create login redirects and logout redirects.</li>
<li>Allow/deny access to specific posts based on user roles.</li>
<li>Hide plugins on the Plugins -> Installed Plugins page from other users.</li>
<li>Edit the display name, description, and other plugin details shown on the Plugins -> Installed Plugins page (e.g. for white-labelling).</li>
</ul>
Shortcodes
The plugin provides a few utility shortcodes. These are mainly intended to help with creating login/logout redirects, but you can also use them in posts and pages.
<ul>
<li><code>[ame-wp-admin]</code> – URL of the WordPress dashboard (with a trailing slash).</li>
<li><code>[ame-home-url]</code> – Site URL. Usually, this is the same as the URL in the “Site Address” field in Settings -> General.</li>
<li><code>[ame-user-info field="..."]</code> – Information about the logged-in user. Parameters:
<ul>
<li><code>field</code> – The part of user profile to display. Supported fields include: <code>ID</code>, <code>user_login</code>, <code>display_name</code>, <code>locale</code>, <code>user_nicename</code>, <code>user_url</code>, and so on.</li>
<li><code>placeholder</code> – Optional. Text that will be shown if the visitor is not logged in.</li>
<li><code>encoding</code> – Optional. How to encode or escape the output. This is useful if you want to use the shortcode in your own HTML or JS code. Supported values: <code>auto</code> (default), <code>html</code>, <code>attr</code>, <code>js</code>, <code>none</code>.</li>
</ul>
</li>
</ul>
Notes
<ul>
<li>If you delete any of the default menus they will reappear after saving. This is by design. To get rid of a menu for good, either hide it or change it’s access permissions.</li>
<li>In the free version, it’s not possible to give a role access to a menu item that it couldn’t see before. You can only restrict menu access further.</li>
<li>In case of emergency, you can reset the menu configuration back to the default by going to http://example.com/wp-admin/?reset_admin_menu=1 (replace example.com with your site URL). You must be logged in as an Administrator to do this.</li>
</ul>

Admin Menu Editor

Does just what it says it does. Instantly.

Perfect

I've been a user of Admin Menu Editor and the Pro version for a while now. WordPress backend can get a little messy very easily, so this plugin comes to the rescue, and it does it well.

I wish all the features were free, but the devs need to pay the bills as well :-)

Best option


It allows you to move existing items on the left side menu around and change their icons.


Not Bad, simple to use


Essential for taming the admin menu, due to all the stupid ideas other developers have for their menus!


Essential

Lets you edit the WordPress admin menu. You can re-order, hide or rename menus, add custom menus and more.

OzTheGreat

For WordPress Multisite (WPMU) installs, allows Super Admins to easily manage each users roles and blogs from one 
screen in the Network Admin menu.
You no longer have to go to each blog to change the user’s role. It’s also 
much easier to see which sites a user is associated with.

Multisite User Role Manager

Ajax management makes it super easy to add users to a bunch of sites in the network. Does 1 things really well, more plugins should work like this.

Great for multisite user management

Made adding a user to 20 sites a lot easier than using WP's default interface for that (way less clicking around).

Much easier to assign a user to many sites

I spent about 30 minutes looking at different multisite user management plugins and all of them were either out of date, or tried to do too much. This plugin solved the exact issue I was dealing with: adding a user (with a specified role) to all of my client's subsites. 

Thank you very much. 

I wish you all the best,
Kevin.

P.S. the CSS for the admin screen where you add users to subsites was a bit off for me (in Chrome). The table did not fit the modal background (it hung off to the right a bit, and forced me to scroll even though there was plenty of vertical space). It doesn't bother me but it might bother some other users so I figured I would let you know. 

Excellent plugin - it does what it says!

Manage user roles for each blog from a single screen on multisite (WPMU) setups

Admin Menu Editor vs Multisite User Role Manager