Coderiver.com.ua boilerplate.
I'm using this as a starting template for almost any project now. It includes sprites, assorted mixins (aka code snippets), file structure, jquery+cycle+scrollto (most usable these days). And, that's it.
You need to have Compass installed for it to work properly.
/sass/lib/base - all the mixins and libs needed for us.
/sass/screen.sass - agregates all .sass files.
/sass/main.sass - styles for the mainpage.
I use BEM naming, meaning .block for independent block. .block__element for elements inside that block. And .block_modification for modification of the block.
layouts.sass consists of all the columns-header-footer stuff, all with .l-* prefixes. So you know its layout.
States of the blocks use prefix .is-*. For example .is-running, .is-hidden, .is-open.
Hooks for js should use prefix .js-*.