For audio/video files with no DRM and exist as files on your local network then DLNA will work, there are free DLNA controllers like Skifta and the latest nightly builds of XBMC are also DLNA controllers, the context menu has a Play Using function.
However you do need a DLNA renderer device either for audio which some high end speakers systems support or purchased as an add-on, Netgear sell powerline adapters which have a 3.5mm audio output on them, various media players and dedicated network speaker systems also have this feature.
Open source Airplay is also available via this method with some apps on Androud like DoubleTwist but it only works reliably with open source Airplay devices like XBMC & not all true Airplay devices will work.
For Youtube you need something which has the newest Youtube platform which supports beaming Youtube from a mobile device, a GoogleTV would be the safest bet for this, same goes for Google Play Movies.
For streaming music services your out of luck unless they specifically support streaming to some other device via any of the above methods.