I think .NET is one of the few projects Microsoft maintains that I admire that feel like they care a lot about quality, you can tell the people working on it are focused on performance and making sure its really well rounded. I would argue that .NET is Microsoft's greatest achievement / work of all time.
MS has had very little to do with the execution, but it has their logo on it, so I think you can count most Microsoft hardware (pre-Copilot button) as quality.