Check it out. I make a semantic, responsive, IE7+ page layout with generic styling in 3 minutes from scratch: http://www.screenr.com/gyh7
I sampled all the CSS frameworks for quite a while and actually made a few until I was finally happy with this one.
It's incredible flexible too, you can adjust the number of columns, column & gutter widths, max-width, mobile-width, etc.
It's currently written in Stylus, but I'll port it to LESS and SASS if it gets popular.
Here's the breakdown:
- Semantic.gs - grid system
- ZURB Foundation - one-breakpoint responsiveness
- Bootstrap - inputs, forms, tables, buttons, whatever. You can enable/disable these.
- HTML5 Boilerplate - Cuz..
- Modernizr - Cuz...
- Respond.js - Makes IE's responsive
- Stylus - best CSS preprocessor
- nib - It's Compass for Stylus
- boxsizing.htc - Makes IE work with boxsizing
- Normalize.css - Normalizes css...
This combo makes for some awesomely fast frontend dev.