Every state has their own rules for how much coverage you'll need. But generally, riders are required to have bodily injury and property damage coverage. Those sound pretty important … because they are!
If you're ever at-fault in an accident, bodily injury and property damage will mean you might not have to foot the bill (depending on your deductible and limits) for the other driver's medical bills or car repairs — or other stuff that gets damaged, like their fence.
Other coverages, like comprehensive and collision (which are optional) could help repair YOUR bike if it's damaged in an accident … or even if it's hit by a wayward tree branch or a nasty hail storm.