InstaGator
Of course, I like frames. Left side content, with folders containing threads. Folder categories contain relevant threads. User controls that include the ability to change colors, font size, posts per page, where I want the Start page to be.
Scrolling should be kept to a minimum, with the ability to access posts within number ranges, and selectable posts per page. Interest ratings for threads.
As I have mentioned before, there is a lot of wasted space on the page that could be utilized. Maybe if the desktop view is used, that will change. Ease of use and navigation are of paramount importance.