I always feel the need to use quickdraw and maybe even stalk on all my assault rifle and light machine gun classes. On my shotgun classes I feel the need to always use long barrel or silencer. On the snipers I always use the reduced sway thing and I almost always use ghost, toughness and dexterity on all my classes.
I really wish I got the same Toughness everyone else gets. Every time I try to use it, I still die before I get a chance to do anything. Pretty much every kill I've gotten with it has been one I've had gotten without it.
Anyway, for me, the only absolute is Engineer.
"The world is full of kings and queens, who blind your eyes and steal your dreams It's Heaven And Hell!" Black Sabbath- Heaven And Hell
I agree with emp grenades, ever since i fought that party in TDM that camped with shields and all the perks that resist things. As long as I use the emp on the other side of the wall, not even trophy systems can block me from blowing up their stuff.