Combining two versatile words such as Fuck and Shit yeilds an extreamly versatile combination. Fucking Shit can be used to exclaim dismay or excitement, just about as versatily as either of its component words.
p1: Dude, I just got into a fender bender
p2: Fucking shit man, how bad is it?
p1: I just got 500 bux in the mail for no reason!
p2: Fucking shit!! You bastard!
p1: Fucking shit that test was hard...
p2: Hell yeah!