Windows/Mac/Linux: VLC, one of our favourite video players, has just updated with experimental support for Blu-Ray discs, not to mention a seriously overhauled interface for Mac users.
VLC just hit the 2.0 milestone, with it bringing a ton of behind-the scenes improvements to video playback on systems with multiple cores and fast GPUs, plus a number of new supported formats. Mac users will be overjoyed to find the Windows 95-esque look gone, with a sleek new black window in its place. The new UI also has an iTunes-like library view, pushing VLC beyond "video player" territory and more toward a media manager.
Lastly, VLC 2.0 has experimental support for encrypted Blu-Ray discs, meaning you don't have to rip your Blu-Rays before watching them. It doesn't support menus, and it can be a little wonky with certain discs, but if you have a Blu-Ray drive, it's worth giving a shot. Note that you'll need to copy a few extra files to your system to support this feature, since VLC hasn't bundled the necessary decryptors with the main installer.
VLC is a free download for Windows, Mac and Linux users.
VLC Reaches 2.0 [VideoLAN]