A lot of variables to consider. Are you in a high theft area? Is vandalism common where you live? Is there a high risk of storm damage (hail, wind, flood)? Is the vehicle parked in a garage, driveway, or on the street? Do you often allow others to drive your vehicle? How much will you save dropping certain coverages? What is your tolerance level for financial risk?
In the past, we have dropped the collision piece but kept liability (required anyway) and uninsured/underinsured coverage. Understanding that by doing so any vandalism, storm damage, etc. or repairs due to my being at fault in an accident would come out of my pocket. In our case, the vehicle was garage kept, never taken to sketchy areas, and driven in areas of light traffic. Thus, risk was relatively low. Savings was not huge IIRC, but enough that I was willing to shoulder the risk given the circumstances.
Think it through, and if you want to drop coverage be sure paying for repairs due to an accident won't put you in a bind financially.