Disadvantages: Connected TVs aren't particularly versatile. If your set-top box doesn't have a channel you want, you can go buy a new one, but you won't be able to do such a thing so easily with a big, expensive HDTV. Also, if you're big on live TV, you'll still need your cable-TV subscription, as the Internet features are mostly on-demand video only.

Advanced tips: Most connected TVs include USB ports and DLNA support (see the glossary on the second page, near the end of this article), meaning that you can watch your locally stored video, photos, and music from a USB drive by plugging it straight into your TV or from other PCs on your network--handy for the times when the video you want to watch is sitting on your PC in the den.

Future-proof? Yes--but only if you choose wisely. Although early Internet features in HDTVs looked pitiful compared with what a standard set-top box could offer, the big players in the HDTV market (LG, Panasonic, Samsung, Sony, and Vizio) are each looking to make their Web-connected TV sets your entertainment hub by adding new features, video channels, and even their own app stores. For example, Internet features include Facebook, Skype, Twitter, and even downloadable games from Gameloft in addition to a whole host of media-streaming services like Amazon Instant Video, Hulu Plus, Netflix, and Pandora.

A relatively inexpensive, simple, and easy-to-install way to add more channels to your TV, set-top boxes vary in size, shape, and content selection. They rely on your home Internet connection to stream media from Internet sources such as Hulu, Netflix, YouTube, and many other video-on-demand channels. Consider them a supplement to your cable subscription, rather than a replacement, since they won't have much in the way of live TV programming.