America's Test Kitchen did some testing and the Breville was their top pick:
* https://www.youtube.com/watch?v=_IRAi6Nzxbk
The Wirecutter has Panasonic and Toshiba, with Brevilles as an alternative:
* https://www.nytimes.com/wirecutter/reviews/best-microwave/
I have the Toshiba and am generally happy with it.