We use slingbox and love it! We never miss any of our favorite shows from the US.
We set our home computer up to our 40" TV and stream all our favorite American shows onto our television. It is also set up like a TiVo. You can pause, rewind, record your favorite show and watch them later!
We bought the Slingbox PRO-HD so that we can watch our shows in HD. The picture quality is pretty good, but probably not as good as you would get it in the states. The Slingbox costs between $200 - $300. You will give your Slingbox hardware to s/one in the states and you keep the software. Pick s/one that has the best cable channels because you will get exactly the same channels they get. That person will also need to have high speed internet connection (the faster, the better).
There is no monthly charge to use the Slingbox. It can be used anywhere in the world. When we first arrive in Japan, we watched TV from our laptop. Once we got all our furniture, we hooked our computer up to our TV and up popped all our favorite TV shows! You have to play with it a bit to get it to play just right. It skipped a bit at the beginning, but we managed to fix all the little kinks and are very pleased.
Don't bother paying for expensive cable in Japan. Just make sure you get a good, fast speed Internet connection. So, go buy a big flat screen TV and a Slingbox and you will be one happy couch potato!