There are six Great Fairy Locations throughout Hyrule. Below, I've listed each Great Fairy Location along with the gift each one has for you. Find 'em all!
First Great Fairy Fountain - If you follow the path up Death Mountain, you will find a bombable wall right beside another entrance (Death Mountain Crater). Bomb the wall with a bomb. This Great Fairy will give you the ability to perform a spin attack on your sword. You will also have a magic meter from now on.
Second Great Fairy Fountain - Follow the path leading to Hyrule Castle. You will see a huge boulder and a sign. If you bomb the boulder, you will find the entrance to the next Great Fairy. This Fairy will grant you Din's Fire, a powerful fire attack that consumes a lot of magic power. You can use this magic to light torches as well.
Third Great Fairy Fountain - In Zora's Fountain where Lord Jabu-Jabu (the big fish) dwells, go to the island located behind Lord Jabu-Jabu. Bomb the wall behind the grey boulder to reveal the entrance to the next Great Fairy. This Great Fairy will give you Farore's Wind, a magic spell that can only be used in dungeons as a warp point.
Fourth Great Fairy Fountain - If you get to Death Mountain Crated, from the entrance, head right, jump across the ledge, climb the ladder until you reach a huge boulder by the wall. Smash it with the megaton hammer to reveal the entrance to the Great Fairy Fountain. This Great Fairy doubles the size of your magic meter, which is quite useful!
Fifth Great Fairy Fountain - Near the Spirit Temple, you will find a crack in the wall. Look around, you'll find it. Blow up the wall to reveal the next Great Fairy. This Great Fairy will give you the third magic, Naryu's love, a magic spell which provides you with a strong barrier to protect you against enemies for a limited amount of time
Sixth Great Fairy Fountain - With the golden gauntlets, near Ganon's Castle, head right. Use the gauntlets to lift the huge stone pillar and reveal the entrance to the final Great Fairy. This Great Fairy will double your defensive power, and you can see the evidence, as the hearts will have a white line around them. Pretty cool, huh?