If an FPS I always go with an AR because they are normally well rounded and I hate having range restricting weapons where you need to either keep at long range or keep at close range I like to be able to takedown anyone whether they are close or long range.
But if in a rpg style game I like to go for weapons that have high power even if they are slow because I like to make my hits count rather then having to put 10 hits into an enemy to take them down.
My favorite weapon in video games is the Zweihander sword Requiem from the game Soul Calibur: And I also like the sword Soul Calibur from the game... Soul Calibur... XD