Obviously this varies by hospital, but talking with my classmates here's how I'd rate it by specialty for DO programs.
"Required": Ophtho, Anesthesia, Radiology, Derm, Urology, ENT
Highly recommended: General Surgery, Ortho*, NeuroSx, EM
Helpful: Neurology, FM, IM, Peds, Psych, Ob/Gyn
Not Needed: Traditional Rotating
*(Ortho could probably go under "required" but due to the large number of DO spots in the specialty I gave it a "highly recommended")
In general though, I think you find that the majority of people who matched to their 1st choice rotated at that program.