How do watch tv from your laptop?

I want to watch tv threw my laptop. How to connect my laptop to my tv

buy this: http://www.amazon.com/PCTV-Stick-USB2-HDTV-Tuner/dp/B000IM5GAO

I have one, it works GREAT. You can either hook up a landline cable line into it, and whatever channels that cable gets, you can watch and/or record, or it also comes with an antenna. It works though USB and it's HD too! The over the air HD channels are great. You only pay once to buy the unit, there's no service charges or anything. It also can stream internet radio, and the device itself has a small adapter that it comes with that has an RCA input, and S-Video input, so if you have a video game system, you can use this to use your computer as like a display for your system. This is not only great if you don't have a TV around, but you can use the software to record footage in game, so you can make like instructional videos for youtube. You can also use it to convert VHS tapes to DVDs through the computer, and much much more, the possibilities are endless. If you have any questions about it, feel free to just post them as a comment here. I've had mine for about 6 months now, so I can tell you pretty much anything you want to know.