The Zelda games have had many visual changes over the years, including the healing fairies. So here's a chronological list of their changing looks.

The Legend of Zelda - 1987

Made for the NES, the graphics were simplistic and color-selective. Seldomly found, these fairies had the annoying habit of hovering over bushes & walls were you couldn't get to them. It's like they wanted you to lose. =/ These fairies wore a crown, and healed ? hearts.

Adventure of Link - 1988

Also for the NES and used the same design. These fairies usually appeared in the overworld when Link was hurt (see left image), and when you walked into them you were taken to a side-screen view (right image) where if you jumped up to them they would fully heal you. A short "fairy tune" played at the intro.

A Link to the Past - 1992

Originally for the SNES, and then later ported to the GameBoy Advance. As you can see, the fairy design improved with more color options and better screen resolution. The crown was replaced with antennas, and they now carried a wand. This game also introduced the concept of catching fairies and placing them in a bottle, where you could have them heal you at a later time.

Link's Awakening - 1993

Made for the GameBoy then released for the GameBoy Color. I often mistook these fairies for little crickets. ^^; The design seems to be a hybrid of the NES & SNES fairy styles; Antennas instead of a crown, but no wand. These fairies could be found in bushes and pots, but you couldn't catch 'em in a bottle. (Healed 6 hearts)

Ocarina of Time - 1998

Ah, the first 3D Zelda game for the N64. A first for their kind, these fairies took glowing-orb forms instead of the normal humanoid look. A grand choice in my opinion. Their soft colors and sparkling trails added beauty and mystique to their amazing world. Plus, they could be found everywhere and you could store them in bottles.

A cool thing to note, you can play either Zelda's Lullaby or the Song of Storms for any of the Gossip Stones found in Hyrule to make a fairy appear.

Majora's Mask - 2000

Also for the N64, used the same engine as OoT so the graphics style remained the same, if not more vibrant. And like OoT, healing fairies could be found around every corner.

Oracle of Ages & Seasons - 2001

Released simutaneously for the GameBoy Color. These healing fairies are exactly like those in Link's Awakening, except they're pink. Can be found in bushes and pots, can't be captured in bottles, and healed 6 & 1/2 hearts.

The Wind Waker - 2003

The third 3D Zelda game, and released on the GameCube. These healing fairies returned to the humanoid style, this time donning yellow pigtails and trashing the antennas and crown. They do however, keep the wand. These fairies could be found on most islands hiding in pots & in fountains, could be held in bottles, and healed 10 hearts.

Four Swords Adventures - 2004

Made for the GameCube, but also used the GameBoy Advance. Although it uses the same graphic style as The Wind Waker, the set-up works differently. They're called Force Fairies in this game, and instead of catching them in a bottle, they are stored in the Four Sword. There was no limit to how many you could keep, and as long as you had some, one would always revive you if you died.

The Minish Cap - 2005

Made for the GameBoy Advance with wonderfully detailed graphics, this game followed the Wind Waker visual style. These little fairies look exactly like their 3D sisters, except they only heal 4 hearts.