I mostly agree with what Toujours said. Unova has introduced 5 more Pokemon than Kanto, has had more interesting character designs, some very strong Pokemon and also has more Legendary Pokemon.
Also, unlike Kanto, Unova has actual cover Legendary mascots and Kanto only had its starters as the version mascots. Also, the Legendary birds are very frail and aren't helpful in battle at all, not to mention the only Uber they have is Mewtwo.
I also never played any Kanto games, and Unova is my fave region which explains this. And in terms of starter designs, Unova is better than Kanto.