[8372049]

And just six years between that and HL2/Doom 3, the first big games to introduce proper physics. Shooting a box and watch it move, or the pick up a soda can/shipping container and throw it around was mind blowing at the time.

Not to mention the graphics evolution; compare G-man from HL to HL2.

[kridsdale3]

Deus Ex didn't have full "the cube can rotate" physics but it did a lot to move this kind of thing forward. You can totally throw a can of soda at a cop.

[8372049]

And Splinter Cell (2002) had curtains that moved around you as you passed under them. Many games had individual features that were innovative physics-wise, but I still think HL2 and Doom 3 were the big mind blowing ones, both for me personally and the media coverage at the time.