Launch date: September 18, 1996
Fatal flaw(s): Weak web browsing experience
WebTV was ahead of its time. Launched when most people still didn't really know what to make of the Internet or how to use it, WebTV attempted to bridge the gap by allowing people to surf the web through the device they used the most: their televisions. And for a while it worked. Companies like Sony, Philips, and Samsung building set-top boxes for the $20/month service. It was doing so well, Microsoft took notice and bought the company, eventually turning into MSN TV. The thing that really killed WebTV was time. As people became more familiar with the Web and computers became more mainstream and easier to use, paying for an Internet service that only worked on your TV seemed a bit silly.
Fun fact: WebTV, after being purchased by Microsoft, worked with Sega to put WebTV in its Dreamcast console. Running over Microsoft's Windows CE OS, it was the first console to sport an Internet connection and browser, and lead the way for Microsoft's development of its Xbox Live service.