PeoplePress

It is currently in early stage of development and provides very basic functionality. 
We are looking forward to add more functionality with our upcoming releases.
Currently it offers login, password reset and a basic user profile with default fields.

It is lightweight user profile and account management plugin.

Matt Burnett

The Require Login Plugin allows you to easily restrict access to your WordPress site to only users with login credentials, Providing functionality perfect for intranets or restricted development sites.
Below are some of its features:
<ul>
<li>Require users to log in</li>
<li>Customise login page</li>
<li>Redirect users after logging in</li>
<li>Custom login logo support</li>
<li>Disable password reset and “back” link</li>
</ul>

YumJam Require Login

Disable the public site functionality, always prompt for a login before showing any content, make WordPress and intranet style site

PeoplePress vs YumJam Require Login