Mines: Forget it. Old habits die hard for me, so I still give Engineer a whirl, and am good at it. But there are too many blind people playing the game who drive right into mines. (Not that I have anything against braille keyboarders!!) And since 1.03 any fool can remove my mines with a grenade, so the class is ruined.
Karkand: I think MEC should blow, esp in 32 man.
Dqng: About the only map where taking out a bridge might count as offense, if you are USA, on the two leading out of CH main.
The rest are pretty much by strategy/situation, in order of importance: Zatar, Clean Sweep, Mashtuur, Kubra, Dragon Valley, GulfOman, Wake, Fu-She.
Sharqui: Don't ask me for resupply if you wasted your C4 on a bridge here, dumbass.
Dalian & Songhua = huh?