The Logitech Harmony Hub is one of the best Alexa-compatible accessories out there, and you can get it bundled with a cheap Echo Dot right now.
If you aren’t familiar, the Harmony Hub is a little puck that blasts out RF signals like a TV remote to control all of your devices (Logitech’s database has nearly 300,000; it’s pretty comprehensive). Normally, this would work with a Harmony remote to control devices that are hidden behind cabinet doors, but it’ll also work with just your voice if you own an Alexa device.
So, for example, you could say “Alexa, turn on the TV” to turn on your TV, change to the correct input, turn on your cable box, or whatever else you programmed it to do. The same holds true for your smartphone; just open the Harmony app, and you’ll have full control over your entire home theater.
The Harmony Hub costs about $75 on Amazon (though it’s sometimes bundled with a barebones remote for about $70), but right now, you can get an Echo Dot bundled in for just $15 more.