Walt Mossberg surveys the options; on related notes, see Apple Acquires Matcha.TV (WSJ) and Why Apple TV Is a Cord-Cutter’s Gateway Drug (AllThingsD)
"Should you buy a "smart TV" to watch, say, Netflix? Or should you make an older TV "smart" by attaching a box that includes Netflix? Or should you buy an adapter and just beam Netflix wirelessly from your smartphone or tablet? And then, should you stream a movie or download it? Do you have to pay to get TV shows and movies from the Internet, or can you get them for free?The Many Internet-Video Options for TVs - WSJ.com
There's no one right answer for everyone, or every situation. To help sort out the choices, here's a primer for watching Internet video on a TV, legally."