Amazon Echo & Echo Dot
The Amazon Echo and Echo Dot are a huge part of my smart home setup and they should be a part of most if you are comfortable with voice controls.
I primarily use the Echo Dot, because it is small and affordable so I can install it in multiple rooms. This model can be found for $29 when on sale and it can connect to speakers by Bluetooth or with a 3.5mm cable.
The Echo is larger and it includes a room filling speaker. This is the model my parents use and they love the ability to play music as well as control smart plugs. The Echo is $99, but you can find it on sale for $79 around most holidays.
Here's what the Echo & Alexa can do, which explains many of the smart home controls you can use. I use it for music, lights, plugs and a few other controls.