Recently, I got bored of World of Warcraft and reinstalled No One Lives Forever and the sequel. I cranked it up to SuperSpy (the "hardest" mode) and played away. While SuperSpy was still pretty easy, I had a complete blast playing it. My only regret was that Monolith hasn't done a "rebooted" version of NOLF with newer graphics, harder enemies and a stricter weapon system (NOLF has that problem of multiple weapons which do exactly the same thing.)
The story line is great, especially if you're a fan of Bond movies, the Avengers TV series and other sixties spy films. What makes it even more fun are the side conversations and events. I can't think of any other game series where I stopped an attack just to listen to the hilarious conversations between enemy characters.
I would love to see a NOLF revisited and a No One Lives Forever 3.