Vampire
Let them in!
Yes Joomla! has it's own password reset built-in, yet sometimes users need something even easier. This is especially when you're launching a new site from a migration where there are lots of users but their logins have to be re-created. Vampire is a very simple way to get your new site established.
Just their email address...
Using Vampire your users only need to enter their email address. It looks on the database and when matched creates a password and sends the new login to the user. You can add some text to start and finish the out-bound email too so your message along with their new login is tailored. They can of course change their password once they've logged in.
Please note the free version includes links to external sites such as oxfam etc.