For the best quality and easiest set-up within Windows 7, Media Center should be used to stream media to your TV. you'll need a Media Center extender, which come in many forms, from an XBox 360 to little set-top boxes to HP's MediaSmart TV, which has Media Center Extender capabilities. Once you get the required components, you will need to start the media center extender and configure it via PC's Media Center application. Once that's done, you can set Media Center to watch folders for permanent media - all your music perhaps, but more importantly, you can instantly stream any supported files to it from any computer. Given that the extender is visible on your home network, you can right click on any supported file (pics, vids, music) and select "Play To" and select the extender from the pop up list.
I just discovered the instant streaming feature - I previously used watched folders. As this is nice for permanent data, I like that you can instantly stream anything w/o having to copy it over to a watched folder. This works through my laptop even though Media Center is configured on my desktop machine.
Pretty slick, MS - don't give up the eHome project.