I am using several of them throughout my site
http://ucweather.org/ I have a display that shows the WWA's fror my area (San Francisco Bay Shoreline), another using the state feed that displays all the WWA's for California, another that uses the feeds from the NWS West Coast/Alaska Tsunami Center and PTWC feeds to display the tsunami bulletins, and yet another using the national feed that only displays the national warnings.
I also set up some separate pages using a combination of the SPC, NHC, and watches, warnings, and advisory feeds.
Tornado/Severe Thunderstorm and Flash Flood Warnings
http://ucweather.org/stormauto.php Hurricane/Tropical Storm Watches and Warnings
http://ucweather.org/hurricaneauto.phpWarnings Only for all U.S.
http://ucweather.org/warnauto.phpI also have another page that uses all 50+ hydrologic feeds from AHPS
http://www.weather.gov/ahps/ and displays the alerts on one page.
http://ucweather.org/allahpsalerts.phpI guess they are all my favorite and I just like to know what is going on around the state and the U.S. without having to go to a half dozen different websites.
Harry