How? They aren't ugly in the first place. In fact they're eminently readable and navigable.
* Tight line spacing
* Full window width lines
* Small fonts
* Sometimes, font choice
When I'm reading something lengthy on a site like those named, I'll usually set a max-width on the body, give it auto margins, and play with line-height, font-size, and usually set it to Arial. Takes me 30 seconds on pages that aren't terrible and makes it much easier to read. javascript:(function(){function d(a,b){a.setAttribute("data-css-storage",b)}function e(a){var b=a.getAttribute("data-css-storage");a.removeAttribute("data-css-storage");return b}var c=[];(function(){var a=document.body,b=a.hasAttribute("data-css-disabled");b?a.removeAttribute("data-css-disabled"):a.setAttribute("data-css-disabled","");return b})()?(c=document.querySelectorAll("[data-css-storage]"),[].slice.call(c).forEach(function(a){"STYLE"===a.tagName?a.innerHTML=e(a):"LINK"===a.tagName?a.disabled=!1:a.style.cssText=e(a)})):(c=document.querySelectorAll("[style], link, style"),[].slice.call(c).forEach(function(a){"STYLE"===a.tagName?(d(a,a.innerHTML),a.innerHTML=""):"LINK"===a.tagName?(d(a,""),a.disabled=!0):(d(a,a.style.cssText),a.style.cssText="")}))})();
I also use Stylish and Greasemonkey to style and script any sites I visit frequently to match my personal tastes and add missing functionality or helpful features.