I currently have 4 of them set up, bedroom that we're in while we refinish the Master, living room (open floor plan so can also use it from the kitchen), basement/media room, and fish room/future bar room. I also have 2-3 more in boxes left over from when we gave them to everyone for Christmas - I think we had ordered 12 to give out as gifts. I plan on setting up at least two more so that both guest rooms have one as well.
I use them to automate the ceiling light/fan in the living room (Alexa, turn on the fan), the basement lights (Alexa, turn on the basement lights), a reading lamp in the living room (Alexa, turn on the reading lamp), my wife's bedside lamp (Alexa, turn on Catie's lamp), the light over my QT tank (Alexa, turn on the QT lamp), and now the ceiling light/fan in the master bedroom (Alexa, turn on the master). I use a mixture of TP-Link switches and outlets (get the minis, they only take up one outlet) as well as the Phillips Hue system for dimming bulbs. I think I still have one switch and one outlet lying around to install. I would like to put one on our front porch light since you can also control the switches remotely or via a schedule, very useful when travelling. I also will finally be tidying up my wiring on the tank and will use a Quirky outlet (controlled by Alexa) to be able to turn off filter/skimmer/power head for water changes or feeding until I upgrade and implement an Apex into the new tank.
Aside from that, we play a 6-question Jeopardy game every night (Alexa, play Jeopardy), listen to Spotify/Pandora/
Amazon Music, use her as a timer or calculator or converter, and ask her stupid questions (Alexa, sing me a song, what is the meaning of life, what sound does a cow make, do you love me, when will the world end, etc).