Depends on how much you want to invest.
I have a ROKU box (Abt $70) (requires a router so it can work off the modem for the Internet) to connect to the TV. With ROKU, I also have Netflix (subscription $9/mo). Hulu and Amazon Prime are other subscription services that operate through ROKU.
With ROKU, you can also add the PLEX channel. The PLEX software is available free. PLEX can connect via your computer (it has to be on) to the Internet to access videos on many TV networks and various video websites. PLEX then plays them through ROKU on your TV.
Netflix/Hulu/Amazon have many movies and TV series. Hulu adds short commercials throughout. Netflix and Amazon are commercial free.
Ditto everything TomGuy said, plus: spend a one-time $50 charge on the Roku private channel called PlayOn http://www.playon.tv/
Along with the standard channels that PlayOn comes with, you can also add several private channels/scripts (most are free) and you will have all the programming you will ever need. http://www.playonscripts.com/
Here are the private channels I use most:
1channel (free) tv shows and movies
ProjectFreeTV (free) tv shows and movies
Superusvox (one-time $5) live cable tv
Vipbox (free) live sports
Playon only works in standard definition. You need a Roku player (or other streaming device) to send it to your tv and you need a newer computer and medium-speed internet. I have had it over a year, it’s the best deal out there!
As far as I can determine, the Roku is basically a media-streaming device, which I can put together from a spare older computer without much difficulty, so is it more than that somehow?