If you want to have as much space for websites in your browser, without using a fullscreen mode - then choose Firefox. It's the most customizable browser in the market and my personal favorite. I do use Chrome though for when sheer speed is most important.
There are a few tricks to cramming as much interface as possible in the smallest space. I've come to a point that I can't really compact it anymore ;) The whole visible interface consists of a menu bar and a tab bar. The whole interface has a height of 41 pixels ;]
The extensions I use to achieve such a compact interface are:
Classic Compact (theme) and its companion extension Classic Compact Options
Download Statusbar (downloads on a bar, like in Chrome)
FireGestures (any mouse gestures extension will replace the arrow buttons)
Hide Caption Titlebar Plus
Omnibar (combine URL and Search fields)
And a couple custom Stylish userstyles
I'll update the post will additional details and tips later.