As you have no doubt noticed GameDev.net has undergone some fairly radical changes recently; most of these seem to be for the better, but as with any change there are some downsides. GameDev.net is a large and busy site and the sheer volume of forums can be a little overwhelming. One feature that was available with the old forum software that I have not been able to find in the new software is the ability to flag certain forums as your favourites and to have a short list of these at the top of the forum listing.
To restore this feature I have written a small userscript for Opera and Firefox (using Greasemonkey). Chrome apparently has some support for Greasemonkey-style userscripts so the Firefox version may work there -- I'm afraid I do not have it to hand to test.
You can add a forum to your Watched Forums list by clicking the Watch Forum button at the top of its page. I hope you find this as useful as I do!
Update: I've modified the userscript to work with collapsed categories. If forums in collapsed categories are missing from your favourites please update your copy of the userscript using the download links above.