Kim Komando and Leo Laporte are probably the two most popular computer talk show hosts in North America. Kim calls herself 'The Digital Goddess' and her weekend radio show is on more than 450 radio stations. Leo is 'The Tech Guy' and is on 60 stations and XM Radio (Channel 158). Both shows cover the range of popular home electronics.
Kim and Leo are smart people (Kim graduated high school at 16, Leo attended Yale). Each have had tech shows since the early or mid 1990's. Both are good at self promotion. Kim's show, website, and digital persona are much more controlled. Leo is much more interactive with his fans: often there are more than a thousand listeners in the IRC chat session during his show. Extensive 'show notes' are maintained for each episode of 'The Tech Guy'. Some of Kim's USA Today column (CyberSpeak) articles are interesting.
Kim does a lot of teases for upcoming calls which often make them sound like they will be more interesting than they end up being. She includes some irritating background noises (examples: fake applause and chanting of "We're not worthy!") in her show.
In addition to his radio show, Leo runs TWIT.TV and is in many of its shows. Virtually all of Leo's shows are available free. To access Kim's shows costs from $5.95 a month to $49.95 a year.
Leo is a true gadget freak and buys most of the popular new phones. He is also seems to be a fairly serious photographer. Leo has a pool of experts who he draws on for additional expertise (such as Ryan Shrout for computer hardware, Paul Thurrott for Windows, Steve Gibson for Security, and Jeff Jarvis for media). My favorite show on TWIT is 'This Week in Google'.
Leo and Kim's wikipedia pages provide additional information and pointers to their primary websites. To my taste, Leo has a much higher signal-to-noise ratio of the two.
Update On Mar 27, 2010: Kim Kommando has recently started TVKim, but you need to pay about $6 a month (apparently without a free trial). I will stick with TWIT.TV, which is free and definitely has more content. See the image on early web statistics of TVKim vs TWIT.