That's a lot of what I use. Here are some others.

http://www.theregister.co.uk/tonys/slashdot.rdf
http://www.infoworld.com/rss/news.xml
http://www.winoscentral.com/backend.xml
http://rss.pcworld.com/rss/latestnews.rss
http://www.betanews.com/rss2

A few more that Island Dog didn't already list;

Science
http://news.nationalgeographic.com/index.rss
http://science.nasa.gov/rss.xml
http://news.bbc.co.uk/rss/newsonline_world_edition/science/nature/rss091.xml
http://www.npr.org/rss/rss.php?topicId=7

BBC
http://news.bbc.co.uk/rss/newsonline_world_edition/front_page/rss091.xml

NPR
http://www.npr.org/rss/rss.php?topicId=2
http://www.npr.org/rss/rss.php?topicId=3
http://www.npr.org/rss/rss.php?topicId=4

I use RSS Reader, hadn't tried Blog Navigator yet. RSS Reader allows you to track multiple feeds also.

I use Sage on Firefox

Well...
You can never have enough of joeKnowledge:
http://joeknowledge.joeuser.com/rss/joeknowledge_rss.xml

Autoblog:
http://www.autoblog.com/rss.xml

CNET has a few RSS feeds to subscribe too:
http://news.com.com/2547-1_3-0-5.xml

Neowin has a few RSS feeds but here is the main one:
http://www.neowin.net/backend.php?page=main

Yahoo has maaaaaad feeds, just use yahoo search to get at them, oh and don't forget eSource Magazine has a RSS feed too... you might want that.
http://feeds.feedburner.com/eSourceMagazine

Pluck, if your interested, has some cool RSS feeds too that, at times, add to Blog Navigator for eassier blogging and commenting.

If you want, I can share my RSS feeds with you (over 50) from my Pluck account and you can add it to Blog Navigator

Great links. Thank to everyone who has shared!

Gizmodo and LifeHacker are my recommendations. I'm new to RSS feeds myself I didn't really care for CNN's RSS feed, as you can't really read anything from the feed itself.