OS X: Macs can stream audio and video pretty easily over AirPlay, but if you want to watch/listen to your media on a television you need an AppleTV hooked up to get the job done. SofaPlay offers the same functionality, but with the more widely-implemented UPnP/DLNA standards.
If you have a gaming console or modern flatscreen television set, chances are you have a UPnP/DLNA-capable device. In addition to this app, that's all you need to get started with streaming. Just open up the app, drag the media you want to play, and select where you want to stream it from the device list. SofaPlay will take care of everything else and send the file over to your TV. Controls to scrub through the file and mute audio are available, plus you can replay recently used media files through a list you can access in the main panel.
If you want to give it a try before you buy, you can download the "lite" version for free and stream anything for up to two minutes.
SofaPlay ($5) | Mac App Store
