BuddyDev

Brajesh Singh

Disable Site Delete plugin only allows network administrators to delete a blog/site on a WordPress Multisite network. It does not allow blog owners to delete their blogs.
It works by doing that in 3 steps:-
<ul>
<li>Removes the delete Site link from tools menu for non network admins</li>
<li>Breaks out of wpmu_delete_blog function to avoid deletion of blog</li>
<li>hacks around option to avoid sending the delete confirmation mail to blog owner</li>
</ul>
Need more details, please visit this post on <a href="http://buddydev.com/wordpress-multisite/introducing-disable-site-delete-plugin-for-wordpress-multisite-based-networks/" title="Introducing Disable Site Delete plugin" rel="nofollow ugc">BuddyDev</a>

Disable Site Delete

a good simple plugin that does what ist says and does not try to do too much

Works as stated

Disable Site Delete plugin completely disables the site/blog deletion by a non network administrator

cmc3215

Allow users with specific WordPress roles to delete themselves from the Your Profile page or anywhere Shortcodes can be used using the Shortcode <code>[plugin_delete_me /]</code>. 
Settings for this plugin are found on the Settings -> Delete Me subpanel. Multisite and Network Activation supported.
How it works:
<ul>
<li>
A user clicks the delete link, which defaults to “Delete Account”, but can be changed.
</li>
<li>
User is asked to confirm they want to delete themselves.
</li>
<li>
If confirmed, user and all their Posts, Links, and (optionally) Comments are deleted.
</li>
<li>
Deleted user (optionally) redirected to landing page URL, default is homepage, can be changed or left blank.
</li>
</ul>
Settings available:
<ul>
<li>
Enable or disable Network Wide, which applies a single page of settings across all Multisite network Sites.
</li>
<li>
Select specific WordPress roles (e.g. Subscriber) you want to allow to delete themselves using Delete Me.
</li>
<li>
<code>class</code> and <code>style</code> attributes of the delete link.
</li>
<li>
<code><a></code> tag clickable content of the delete link.
</li>
<li>
Landing page URL.
</li>
<li>
Your Profile confirmation page Heading, Warning, Password (optionally require password), Button.
</li>
<li>
Enable or disable delete link on the Your Profile page.
</li>
<li>
Javascript confirm text for Shortcode.
</li>
<li>
Enable or disable Javascript confirm for Shortcode.
</li>
<li>
Enable or disable using a form (require password) instead of a link for Shortcode.
</li>
<li>
Multisite: Delete user from entire Network or current Site only.
</li>
<li>
Delete comments.
</li>
<li>
E-mail notification when a user deletes themselves.
</li>
</ul>

Delete Me

Great!

Allow users with specific WordPress roles to delete themselves from the Your Profile page or anywhere Shortcodes can be used.

Disable Site Delete vs Delete Me