#1 SkyUI
Download it here.
Last but not least is SkyUI, an overhaul of Skyrim's user interface. It is designed specially for PC gamers on the mouse and keyboard.
It's nicer to look at, offers icons in place of text for inventory sorting, and makes the system much easier to navigate with a mouse and keyboard.
In addition to the inventory, it also revamps Skyrim's magic menu, and barter and container menus.