We recently lost all of the old threads on this subject, so it's time for a new one. I personally use Homeseer HS4, but Home Assistant has many followers too. Your imagination is the key here. I use BI5 MQTT to send messages around the LAN. Some of the things I do are:

1. Turn on outside lights at night if BI5 detects motion.
2. Alexa reads out car license plates as they pass.
3. Alexa states "Tim is home" when I pull onto the drive by HS4 recognising my specific license plate.
4.Use BI5 per camera recording triggers on and off for events in HS4.
5. Back lawn was destroyed by crows last year. Now BI5 with CPAI detects "Bird", and HS4 triggers MowBot the lawnmower to wander aimlessly around the garden. Very amusing.
6. BI5 MQTT can output the order in which zones were triggered. You can do different things in HS4 when objects go in different directions.
7. Homeseer has an Onvif plug in, so you can directly use camera logic. This includes the Reolink video doorbell. I have the POE version connected to BI5 and directly sending Onvif messages like "doorbell button pressed" to Homeseer. With a bit of day/night logic, it will call on all Alexa devices when the doorbell is pressed.