I have recently been doing custom Powershell script steps for Octopus deploy to trigger Selenium based UI tests and needed a good way to present the test outcome.
This command line tool creates a nice html dashboard page of the xml:
Support for both NUnit 2.x, 3.x and MSTest
NUnit HTML Report Generator
NUnit Test Results Viewer
‘NUnit Test Results Viewer’ is a free open source project that allows to view NUnit resulted *xml file.
If tests are triggered from TeamCity or VSTS (Visual Studio Team Services) they have test report tools built-in.