Below are the links that offer the best selected joomla 1.5 free templates that are widely used and most downloaded. No Membership needed, you just need to click the download button.
1. http://www.rockettheme.com/joomla-downloads/113-free
2. http://www.joomlart.com/forums/downloads.php?do=cat&id=145
3. http://www.joomspirit.com/free-templates.html
4. http://www.templateplazza.com/free-joomla-1.5-templates/
5. http://www.joomlapraise.com/free-joomla-templates/demi-joomla-template.php
6. http://www.joomlapraise.com/joomla/templates/free/dailypraise-redux.php
7. http://www.yagendoo.com/en/joomla/joomla-templates/city-sky.html
8. http://www.bestofjoomla.com/component/option,com_bestoftemplate/task,detail/Itemid,46/id,2554/
9. http://www.bestofjoomla.com/component/option,com_bestoftemplate/task,detail/Itemid,46/id,2720/
10. http://www.themza.com/joomla1.5/