34 Responsive Grid System
34Grid is a responsive grid system based on the “equally distributed columns for each row” layout idea.In contrast to other great grid systems, 34Grid provides equally distributed columns for each row. (and also column complements for inequal distributions). If you’re already familiar with grid systems and responsive web design just create&download a bundle and see what is inside. Else you may start with resizing your browser window.
Base
Base is a super simple, responsive framework built to work on mobile devices, tablets, netbooks and desktop computers.
Kube
Kube – A minimal and responsive CSS framework
The Kube Framework is not an overblown responsive CSS framework with multiple layouts and styles, all you have with Kube is a single CSS file. That is were its beauty lies – in its simplicity. The framework also supplies LESS files for the gurus out there who enjoy preprocessing.
Homepage: http://kubeframework.com/
You are missing IVORY Framework, It is better than all other frameworks
http://weice.in/ivory or https://github.com/kanthvallampati/IVORY
Here’s an elegant theme based on Ivory Framework:
http://www.wowthemes.net/demo/salique/salique-boxed/index.html