Edit July 2008: Dont buy their piece of shit software. They still havent fixed AC3. They don’t deliver and give you the ID Sofware reply now (“when it’s done”) or even worse “when the time is right”. I have nothing against giving such a reply, but it’s not cool going from 1-3 months into “whenever” for a deadline. Rip off.
Check out Coreplayer if you can. There was no trial version available for Mac OS X so I bought it just to try it out for 20 USD. The performance on H264/X264 was supposed to be incredible and..wow…I really must agree. It completley blows VLC (ffmpeg) out of the water! My 1.8 ghz Core 2 Duo Mac Mini now plays 1080p movies completley flawless, I’m guessing a speed increase of about 30%.
A big no no right now however is that Coreplayer currently doesn’t support AC3 audio which renders the player somewhat useless, but support is coming and it is coming soon ( within weeks supposedely).