Re: GTA has been dethroned - Sleeping Dogs is the champ now
I wouldn't go as far as to say that it's better than GTA, but Sleeping Dogs is a surprisingly good open world game. The hand-to-hand combat blows every other sandbox game out of the water (unless you included Arkham City; then it's a step back), the driving is somewhat fun, and the shooting is solid. Of the core mechanics, everything is up to standard.
The addition of the upgrade tree provides a small amount of freedom, the atmosphere is decent, the city is a good size and there's a considerable amount of collectibles (clothes, vehicles, upgrades). There's a variety of side-missions, some interesting characters and a well told story.
It's not the best open world game, but it's much better than I was expecting. Equal to Saints Row 3, at least.