Favorite medical alert system and why?

We used GreatCall for my dad with good success. When he either pushed the button on the pendant or fell, it asked him who to call in an order we’d provided. Also asked him about calling 911. If he couldn’t answer 911 was called and then me. There was no dementia, that could change things

The one I chose for my mom and then DH aunt was one connected to a local ambulance service. It’s the only one I’ve used so not familiar with others. When activated, prompt arrivals were impressive. Ask for references.