https://www.thomann.de/de/doepfer_a178.htm
live in action: https://youtu.be/1mIferngPqY
or from stylophone:
https://www.thomann.de/de/duebreq_stylophone_theremin.htm
live in action: https://youtu.be/NNn-se0S4Ww
The Moog Etherwave (Standard/Plus) wasn't the best theremin, but it was always extremely solid in terms of bang for the buck, a standard, easy to set up, reliable option with lots of other players you could ask for help, accessories (carry bag, mods, etc.) so it was the most logical recommendation for most newcomers.
There were (and probably still are) great choices from smaller makers as well, in fact I own one in addition to my Moog, but they were more adventurous choices that didn't offer the reliability and newbie-friendliness of the Moog at a comparable price. Many players would have their pet underdog theremin that they would personally use and prefer to the Moog, but would still recommend the Moog to newcomers because you just couldn't go wrong with it, and others were either expensive, fickle, unsupported, inconsistent quality, difficult to set up, difficult to source, etc. I don't know if newer options will have changed this.