The screenshot in the game look like they went for the hiking boot look, like SEALs (something along the lines of Merrell Sawtooths and similar stuff), but from the pics I've seen the majority of FR/MEU seem to stick to the issued USMC boots -- which are extremely comfortable, I own a pair and love them. They're easily as comfortable as my Columbia hiking shoes (Tigertooths).

And like SINN said, don't use video games for reference for an impression of real units.