Use the most realistic settings?
I like going simplistic... I mean, why would i want wind and gravity to affect my shots?
Hold by your glasses steady! And drink, to your comrades eyes! Here's a toast, to the dead already, and a "Hurrah!" for the next to die!
I play it with realistic settings, because it's a sniper game and I want to feel like a bad ass sniper who can make all kinds of crazy shots. If I want my bullets to go straight no matter what I'll play CoD or something (not knocking CoD, just pointing out that they're different types of games). Getting a long range headshot in a strong crosswind is infinitely more satisfying than just pointing and shooting.
"Uh, 'video game' you say? Well golly gee, you mighty spacemen of the future will have to show me how it works." - Fry
Realistic for sure.
Nothing better than a guy over 200 meters away and you aim your crosshair and due to the wind it's 2 inches to the right of him and over an inch above him. You squeeze the trigger and BAM! Sweet killcam action.