Stand alone? None. There are two built into the TV we bought a few months ago, Alexa and Bixby. They don't seem very smart. The clock in the TV did not auto reset for daylight savings time. I asked both Alexa and Bixby to change the time, nothing. Went into the setup and manually reset the time, but every time I turn the TV off, it goes back to the wrong time.
I have a Google phone, so that accepts voice commands, and I have a Dish remote that takes voice commands, and my tablet has Alexa. Rarely use any of them.