We did that! We have a HD antennae that picks up net work TV (ABC, CBS, NBC, CW, PBS) and we use that for most of our viewing. We also have Netflix and Hulu Plus. Hulu Plus offers a wider variety of shows and movies that the free Hulu. The fee is about $7.99 a month (I think) for Hulu Plus. You have to have Hulu Plus to stream through a device other than your computer.
In order to stream Netflix or Hulu Plus to your TV, you either have to hook up the computer to the TV with an HDMI cable, or have one of the devices that they will stream through. We have an XBox 360 with an XBox Live Gold membership and a wireless router. The Live Gold membership gives us access to Netflix and Hulu Plus as well as several other features. You can go to Netflix or Hulu's website to find out which devices are supported for streaming.
With Netflix you can only stream things that are on their "Watch It Now" list. You won't find anything from show seasons that are currently airing. You can stream a variety of movies through Netflix as well. Most of them won't be super current though We like it because they have lots of cartoons that the kids can watch.
Hulu and Hulu Plus are really nice. You can watch current shows through either. Hulu is the free version and Hulu Plus is the paid version. You can watch a lot of stuff with Hulu, but you'll need to plug your computer into your TV if you don't want to watch on your computer. With Hulu Plus, you get more shows, some movies and you are able to stream through a variety of devices. Keep in mind that you can't always find everything you want on Hulu or Hulu plus. Some cable channels aren't on there. I have no idea if MTV is on there or not.
I'm pretty sure you can watch shows like 16 and Pregnant on MTV's website. I used to watch The Hills on their site.
I would go check out the websites for Netflix and Hulu and see if it will meet your needs. We rarely ever watched our cable when we had it, so I don't really miss it.