Gran Turismo and Metal Gear Solid were written in C. Ken Kutaragi used them as examples of what could be done with efficient programming techniques and good use of Sony's performance profiling tools. (citation needed: one of my old gaming mags that's probably been recycled three times over by now)

It's rather interesting how Sony went from starting with a system that was considered easy to develop for, to having the most complex product on the market--twice in a row!