michaelmurfy: Raspbmc is really easy to install. Just run the installer from http://www.raspbmc.com/wiki/user/windows-installation/ - install it to the SD card, I find that once it's booted it's totally fine to use. Depending on what you're playing I'd recommend buying the codecs, just follow this guide: http://www.howtogeek.com/137654/how-to-add-mpeg-2-and-vc-1-video-codec-support-to-your-raspberry-pi/
With the new version of Raspbmc, they have cracked the video codecs so that you no longer have to pay for them (they had a dispute with the Raspberry Pi Foundation).