I just use it for a few things. My favorite so far is that whenever I add an item to my shopping list via an Alexa device, it gets synced to all my devices as an Evernote list. It's just there on the phone whenever I get to the store.
It also adds to-do's to my Google calendar, sends me a list of new NYT bestsellers, sends an email when rain is predicted (rare in SW New Mexico), sends NASA's pic of the day, quote of the day, compiles a list of every song I've played via Alexa for the past week, etc.
I'll be buying a Logitech Harmony Companion soon, and expect to find a few more uses with that, like setting scenes...
As far as MC, beyond the basic turn-on, select source, adjust lighting type stuff, it might be fun to automatically scrape the top movies/TV/music or a list of most popular playlists/stations... maybe an auto-mood sensor, prepare appropriate beverage, massage -- just the basics. Ha.
I think the best is yet to come, though, as more IoT stuff comes along and prices drop (no, I don't need a video refrigerator, thanks).