First Avenue Machine
Although I am normally loathe to link to a website with such a crappy Flash interface, I will take exception this time. You might recognise First Avenue Machine from a past project called Plants with Eyes. First Avenue is a 3D animation studio who specializes in integrating 3D graphics with live action sequences.
They have a number of really awesome Quicktime videos in the Project section and I recommend that you take some time to watch them.
Link (via Giant Mecha)