In some cases a method is better than a property:

• The operation is a conversion, such as Object.ToString.
• The operation is expensive enough that you want to communicate to the user that they should consider caching the result.
• Obtaining a property value using the get accessor would have an observable side effect.
• Calling the member twice in succession produces different results.
• The order of execution is important. See [7@601].
• The member is static but returns a value that can be changed.
• The member returns a copy of an internal array or other reference type.
• Only a set accessor would be supplied. Write-only properties tend to be confusing.