Those were candidates for Korra's best episode right off the bat. They aren't, but there are only about 3 I'd put above and not by much.
Here are my ratings for the episodes:
A Breath of Fresh Air - 8.6/10
Rebirth - 9.0/10
The Earth Queen - 8.9/10
0- Completely failed. Nothing was accomplished the way it was meant to be.
1- Terrible. Maybe one sequence worked and it's really only worth watching if you REALLY want the full collection.
2- Same as a 1 except it provides some plot worth noting for future issues, or has something that redeems it.
3- Bad. No one would defend it, but fans of the character may enjoy it simply because it's their character.
5- Average. Some will like, some won't. I'd advise researching first.
6- Decent. Fans of the character will rate it as good while casual readers would probably be turned off.
7- Solid. At the very least it's worth keeping up with what happened.
8- Worth seeing. Customers won't feel short-changed, it should be seen, but it won't be a fan-out glorious moment.
9- Must-see. Absolutely worth the price of admission. A satisfying watch all-around.
10- Must-own/Perfect episode. Belongs in a class all its own. I RARELY give something this mark. (Looking back on the MANY animated series I've watched over my life, I'd only say there are 19 or so candidates for this mark across six of the shows.