Responsive template for Joomla 2.5 addressed for web developers, but of course it's only the suggestion. The template is mobile optimised (it adjust to all small screens), includes many configuration settings at the back end, extended typography and many CSS3 solutions to get light and modern design. It's SEO optimized.

Template is available here:

http://www.joomla-monster.com/all-templates/i/5-services/95-jm-web-development

Template's demo:

http://demo.joomla-monster.com/177-jm-web-development