Positive meaning:
Guy 1- Man, this guy's dancing skills is seriously
worth shit.
Guy 2- Yeah man, he's going places.
Negative meaning:
Guy 1- Like my car? I got it just last week.
Guy 2- Haha, man...this car
ain't worth shit.
Sarcastic:
Guy 1- This antique will be worth thousands of dollars in years to come.
Guy 2- Yeah man...it'll be worth some
serious shit...really.