Thief was a GREAT game... It used to STRESS ME OUT!

My all time favorite has to be the No One Lives Forever (NOLF) games. The first one was CLASSIC! They have a goofy 60's spy thriller theme and a great storyline (although the cutscenes were kind of long and tedious). It had the widest array of locales I've ever seen in a game. It starts out in Morocco, you end up in space, Siberia, and there's even one level that's in freefall, falling out of an airplane!

There was an old-school flight sim along those lines (Jetfighter III, I think). I remember the first mission was identifying something they thought was a cruise missile, but it was actually a 727. It had a storyline where the Soviets were attacking southern CA though Mexico. That was pretty cool... (and it came on 2 3.5" floppies)