Call of duty2 best fps ive played.
Realistic:
How your health is managed. There is no really health, if you get shot alot you die. no matter what mode its one.
You acually cant cook the nades.. they just blow up if you have them held for to long.
Unlike most fps AI always aim for the head, well cod2 has ai that aim for every part of the body.
Recoil
If you have the game. Watch the dvd it explains alot more realisitic things...
Not Realisitc:
The german acents where a bit off but the words where accurate.
The german AI die alot ezyer. ( in the editor in coduo it shows that the allies have 500% health and the german AI only have 100%)
The makers of the game... really screwed up. Instead of trying to explain it. i just took a screenshot
http://img105.imageshack.us/img105/4227/shot00791jf.jpg. when your trying to blend terrain in the editor your supose to but and acuall brush under the one you where blending, that way you wouldnt half to worry about this happing.
Thats about all.
I have over 95 screenshots, soon to be more. im takin them for a m8 of mine

If you want the game pure 100+ reallistic play a realsm server...
Im off to finish the game! (i just got it yesterday and i already finished the british adn russain camp. now im working on the allied. w00t