Mark asks, “I have my home PC in one room and my TV in another (same floor of the house). What is the best way to connect the two (to watch movies off of the PC)? Is there a distance limitation with any of these alternatives? In their current locations I would need to run about 25 feet.”
In theory, you could run video out from your PC to the TV using some cables, although a 25-foot run of RCA or S-Video will likely weaken the signal and/or create a bunch of noise in the line. A better option is to invest in hardware designed to stream video from your PC to your TV. This does require using wireless routing for transfer of the video signal, but 802.11g hardware is very cheap at this point.
A bunch of companies are currently making hardware they claim will stream media from your PC to your home theater. The only solutions that work well are the Windows XP Media Center Extenders and the Windows Media Connect compatible devices. The rest of the proprietary options offer solid audio streaming and flaky video streaming at this point. One option is to upgrade your PC to Windows XP Media Center Edition and invest in a compatible Windows Media Center Extender. The second option is to purchase a Windows Media Connect compatible device.
Xbox or Xbox 360
If you already own an Xbox or if you plan on getting an Xbox 360, you’re most of the way to having what you need. The current Xbox acts as a Windows Media Center Extender with an add-on package. This requires you to have Windows Media Center but is a viable alternative.
If you’re really into hacking your media, you can create a low power UHF station in your house by outputting the audio and video from your PC to a UHF transmitter. With the help of a Bluetooth remote like Sailing Clicker to control the PC, simply tune in the video output of your PC on the appropriate UHF station and you’re in business. The hard part here is keeping the signal at a low enough strength to avoid a visit from the FCC.