I used to have a cheap stovetop pressure cooker that I used a couple times a month until it got a bit ... iffy ... so I broke down a few months ago when the Instapot went on one of those Amazon Prime sales, and I love this damned cooker so much. No need to babysit the thing, just push a button, walk away, go to the store, heck, take the kids to the zoo, no worries.
So I basically use it for the same things I used my stovetop pressure cooker for, except much more often (I use it about 3-4 times a week.)
#1 is for making broth/stock. That's my main use for this thing, and it's great. In 45 minutes to an hour I can have an intensely flavored stock that would have taken me 3-4 hours of simmering on the stove. Plus, in the summer, I don't overly heat up the kitchen, which makes my wife happy. I may have bought commercial stock once or twice since buying the Instant Pot about six months ago.
#2 is for stews. Now, I don't throw everything in the pot and cook it all together. Anything that is meant to last the full cook time, I do in the pressure cooker until it's about 75% done, then I finish on the stovetop with the potatoes, carrots, other root vegetables, etc., so they don't turn to mush. (Though you can also finish in the pressure cooker.) I'm not a fan of the "throw everything in the pressure cooker/slow cooker" style of food which reduces everything into a homogenous mush.
If you like Indian food, you will find a lot of Indian recipes that utilize the pressure cooker.
Here's one for a Keralan pork curry. Note the technique of cooking the pork in the pressure cooker, and then finishing on the stove. That's how I use the pressure cooker for a lot of things, too: just to cook tough collagen-rich cuts to tenderness, and then finish them on the stove to save myself about 3 hours of cooking time.
I've also been finding myself use the rice cooker setting on it. I've never owned a rice cooker before, always doing it on the stovetop the old fashioned way, but I do have to say, it's become convenient and frees up some stovetop space for me, plus it has the "set it and forget it" convenience. I haven't tried the slow cooking option on it yet, though.
All in all, the best cooking purchase I made for 2016.