Via Lifehacker:

All you need to do so is a TV out port on your computer and the right cable. Check out the back of your PC or the sides of your laptop for an S-Video port, pictured on the right. (If you don't have one, video cards with S-Video ports are available for under $100.) Then, check your TV's inputs. Many TVs have S-Video ports in so you'll need an S-Video to S-Video cable. If not, an S-Video to RCA cable will work. Connect the computer to the television while the computer's off and the TV's on. Then turn on the computer to give your machine the chance to detect it has an external display available.

Your Xbox or PS3 already has this capability. But, if you want to not fuss with that, Roku has this arena locked down.

The roku won't stream .avi files from my computer though. And I don't have a PC next to my TV, so I want it to be networked via a wireless connection. Yeah, if I had my PC right next to my TV, it'd be easy-peasy.

I'm pretty sure at least one Roku will do that. But, this is made for what you want.

For more flexibility, you want is get a PS3 or an X360, get PS3 Media Server (it works with either console but seems to be more reliable on my PS3) and install it on the computer with your media. Configure the server. Find the server name in your console of choice.. browse content... hit play.

I'd still advise hard-wiring the PS3 or X360 to the network instead of running wirelessly. Also note that if the file has encoding errors a PC may just glitch slightly but keep playing where the PS3 or X360 will simply not play the file at all or stop at that point where the file error exists.

Other options:

• HD TiVo