The game opens with a original Gun Barrel, then segues into Bond spying on the exchange of a nuke. He blows up a plane for a distraction, grabs the nuke and runs for a SAS helicopter that picks him up. We then get the incredible song and title sequence. Watch it here.
Completing any of the Platinum Medal requirements. They're very, very fun, but you really have to stretch your brain.
Defeating Jaws' nano-truck on the Pontchartrain Bridge, not only for the challenge, but also for the feeling that you have just saved a major city.
You can score yourself a minor Awesome Moment in "Red Underground," and here's how: If you use the Q-Spider, you may encounter an "invisible" guard who's just standing around by the next part of the level. If you're far enough from him, and skilled enough, you can give him a sleeper-dart blind (i.e. without locking on).