I was deeply sceptical that the monkey-and-blonde-chick-flick would be anything beyond VFX candy but King Kong (2005) surpassed my expectations. If not for the plot, the cinematography, the colours, and above all the emotive performance of the world's biggest CG character make this a classic.
The godfather of mocap acting, Andy Serkis, has spent quality time hanging out with the gorillas of London Zoo and it shows. On The Culture Show, you can see gorillas responding in the background as he demonstrates a few phrases to the interviewer. One revision on from the process of creating Gollum was the 'Kongalizer', a voice-masking system that allowed Serkis to vocalize gorilla-like on set.