For the purposes of this post, I'll define good usage of Anti-Gravity usage as: "Creating unique tracks designs, that previously wouldn't have been possible without the usage of anti-gravity."
If the anti-gravity is a basic u-turn, or is the track at a slight angle (these two cover 90% of the choices), that's not allowing for more uniquely-designed courses, this is just stuff the previous games could've done.
My choices are the following:
MK8 Mario Circuit - The tracks deisgn is based around being a möbius strip, which should be enough to justify this creating unique track designs.
Twisted Mansion - A section of the track has the path split into two, with each section having the other above it, which wouldn't have been possible without anti-gravity.
Electrodrome - Same thing as the previous track, plus you spend a significant amount of time driving on a wall around a previous section of the track.
Bowser's Castle - Same as above two. I honestly think this sort of thing barely count, but I'm going to be generous as it does fit the presented definition of good usage for the mechanic, and there's only five tracks otherwise.
Dragon Driftway - A majority of the track takes place in anti-gravity, frequently changing which direction the gravity is on. I don't think these tracks require too much explanation as it's fairly obvious just by playing them that this couldn't be done without anti-gravity.
Mute City - Same as the previous track. This one even includes a corkscrew towards the beginning.
Big Blue - Same as both of the above.