Your grad already has your old TV in his bedroom, but he's annoyed that he can't watch all his favorite apps on there because his PlayStation 4 doesn't get WWE. The Roku Stick does, along with thousands of other apps.
If your grad has a bunch of stuff on iTunes, or she just wants something that looks and feels a lot like her iPhone, the new Apple TV is just the ticket. In addition to numerous TV apps it also works with many of the games and other apps she might already own.
Then again, maybe your grad is an Amazon Prime junkie, glomming off your Prime account to binge on TV free shows and movies after recovering from a long school year. Nothing wring with that, but maybe he needs a streamer of his own?
Maybe your grad is grown up enough now to appreciate and deserve a big TV. Our current favorite for the money is the excellent M series, a 4K model with a great picture and a wide range of sizes to choose from, starting at 43 inches.