Minn is another minimal theme (did the title tip you off?). The point of this theme was to see how few template files I could use and still create a decent setup. This theme is composed of four files: index.php (with lots of conditional tagging), functions.php, style.css, and sprite.gif (the arrows in the navigation and sidebar). I could have omitted the sprite and used some other placeholder but it’s 131 bytes so w/e.
It’s entirely possible that this theme won’t work if you don’t have the default theme installed on your system, but I haven’t checked.
XHTML 1.0 and CSS3 valid.
Tested in IE8, Firefox 3.5, Opera 9/10, and Safari 4.
It also supports Yoast Breadcrumbs natively.