In Naruto a colored chapter cover revealed that Naruto becomes yellow with shades of orange when he enters Chakra Mode, as seen here◊.
Purity goes with light in Sailor Moon, and it becomes a common theme (most easily seen in SuperS).
Mobile Suit Gundam Unicorn has Syam Vist, a kind old man in white robes and Banagher Links, who pilots a White Gundam known as The Unicorn that is named after a Beast of Light and Possibility
Angemon and Angewomon of Digimon Adventure are both angelic Digimon with Hair of Gold who both debuted to promptly easily defeat a powerful dark Digimon with their powers of light. Angewomon takes this almost to ridiculous extremes - her partner is Hikari Yagami, whose first name translates to "''light''", and who uses the Crest of Light to make her evolve to Angewomon to begin with. Oh, and near the end of Adventure she started glowing.
Most of the heroes in Fullmetal Alchemist are blondes with gold eyes to boot.
Comicbooks
Superman is powered in part by the light of Earth's yellow sun.
Tangina: When people die, there's a wonderful light as bright as the sun. But it doesn't hurt to look into it. All the answers to all the questions that you ever want to know are inside that light. And when you walk to it, you become a part of it forever.
In Final Fantasy: The Spirits Within the Earth's Gaia is a bright pale blue light that is in direct contrast to the angry red of the Phantoms.
In the first Lord of the Rings film, Arwen appears to Frodo in a flowing white gown with light radiating out from her. This is just a vision to Frodo but it symbolises that she is good and is there to help him.
A bit of a no-brainer but the stars in Stardust. They shine when their hearts are full of joy and happiness although Yvaine actually uses this as a weapon against the witches.
Literature
Night Watch's Light Others live and breathe this trope... though, it can be said that the series examines this trope, bends it, reshapes it, subverts it, averts it, and when all else is lost, the author throws in the towel and pretty much says that all bets are off.
In the Wheel of Time series, the Creator and the Light.
Boktai has the solar child Django and his solar enpowered gun.
In mythology and fantasy stories, light (particularly sunlight) severely impairs or even harms monsters.
The Child of Light (and the Prophecy of Light) in The Belgariad.
In The Dresden Files, sunlight is anathema to most creatures of the Nevernever, and can disrupt more negative and evil enchantments and spells. Also, the Swords of the Cross emit light that cancels out the powers of the Denarians.
Plus the Summer Faeries tend to be fairly benevolent whereas the Winter ones are actively sadistic, although both sides are manipulative and capable of great crimes, when you put the two Courts next to one another it is played fairly straight
The Armor of Light by Melissa Scott and Lisa A. Barnett.
In Robert A. Heinlein's Magic, Inc., the heroes storm Hell because light always overcomes darkness (since darkness is merely the absence of light), and they are the forces of Light, so it does not behoove them to sit around reacting to the demonic forcs.
Diane Duane's Young Wizards series works with this considerably, especially in the first book, although they play with it increasingly through the series and at the end of the third book have a decisive Redemption arc where it is shown that Dark Does Not Have To Be Bad. Of course, the fact that the Powers don't live within linear time means there are still loads and loads of incarnations of the Lone One running around being evil for books and books more, but they've finally given him the chance to start going home.
О Light Invisible, we praise Thee! Too bright for mortal vision.
In L. Jagi Lamplighter's Prospero Lost, Father Christmas tells Miranda, Mab and Mephisto that they can stay a while because all who serve the Light are welcome.
In Teresa Frohock's Miserere An Autumn Tale, only the good guys are capable of casting the light spell.
Live-Action TV
The Ultramen are beings of light and defenders of the universe from monsters and other evils threatening it.
Mythology
In the Lusitanian Mythology, the god Endovelicus was associated with light and healing, being obviously benevolent. However, the same mythology also has Neto, a sun god associated with war, and when Christianity settled in Endovelicus became identified with Lucifer.
Tabletop Games
Exalted gives us The Unconquered Sun, the divine embodiment of virtue and righteousness, created by the Primordial of dickery solely because he wanted to find out what would give him purpose. And boy, did he succeed there, as the Unconquered Sun saw that the Primordials were yoking Creation about and helped lead the struggle to overthrow them. His chosen, the Solar Exalted, are supposed to be like this... save for that little Great Curse thing.
The white colour in Magic: The Gathering uses a sun for its symbol. It has by far the lion's share of cards concerning healing, protection, spells that disarm creatures or only destroy/remove creatures when they attack you, and creatures traditionally associated with good such as angels, knights in shining armour and honest soldiers. Depending on the block, white cards can just as easily make for Light is Not Good, however.
In terms of characters wielding White Magic, the most famous are heroic, but there's a sufficiently large amount of paranoid Knight Templars as well. So light is pretty much neutral in this setting.
Both subverted and played straight with the Living Saints of Warhammer40000. They are shining examples of all that's good about humanity, avatars of the Immortal God-Emperor of Mankind, shining with light that causes most heretics to repent and desire to serve the Imperium, that fills the hearts of the faithful with unshakable courage and joy in serving the Emperor. Within the Imperium, almost universally accepted as unambiguously morally good, serving humanity selflessly in and out of combat and eventually sacrificing their lives for the good of the Imperium. Outside the Imperium, they're probably viewedno better than any other Imperial tool.
Dungeons & Dragons celestials (and more light-oriented creatures) are always good (pre fourth edition).
...actually, any good angel in any story.
Pre fourth edition
The arrows of light from the Zelda games. In The Legend Of Zelda Twilight Princess, the Light Spirits of the four springs, who aid you and who keep the land peaceful.
This trope is sprinkled liberally throughout the games as a whole. Many of the climatic scenes involving Link use dramatic lighting to grand effect - just watch any of the Master Sword sequences. Probably most prominently displayed thematically in The Legend Of Zelda A Link To The Past, where Ganondorf's dark power has corrupted the Sacred Realm (a Golden Land where the Triforce once resided) and turned it into the dangerous and evil Dark World. Subverted somewhat in Twilight Princess.
Amaterasu, the goddess of the sun and mother of all life, in Okami.
In Warhammer 40,000, the Imperial forces continually invoke this trope with the light of the Emperor, stepping from the light of the Emperor, etc. The reality — well, in Dan Abnett's Horus Heresy novel Horus Rising, Loken receives orders to "illuminate" which is to say kill a planet's emperor.
Not quite this trope, as the Great Crusade in the Horus Heresy novels was about bringing humans all over space from the darkness of superstition and religion into the Emperor-given light of science and rationality.
The sheer brightness from the lighthouse in the second DLC "The Writer" is very much One-Hit Kill against the Taken. So as long the boulders are cleared out.
In The Haunted Mansion video game, evil ghosts cannot inhabit a lit room. Every puzzle in the game is figuring out how to light up the current room.
The first Fable has this in spades, with light clothing giving you good points and dark clothing giving you evil points, and good characters morphing to have lighter features. The sequels ease up on it, but it's still present.
In Tangled, Rapunzel, a gentle, caring girl who is a Friend to All Living Things, loves daylight (as well as starlight) and has shining golden hair because her mother ingested a flower that had grown from a drop of liquid sunlight.
Stella from Winx Club gets her powers from the Sun (well, and the Moon, but mostly the Sun), and most of her attacks consist in casting beams of light.
Other
In BIONICLE, every sentient character has a dark side and light side, representing of course good and evil. These could be tapped into, to obtain either light or shadow powers, and naturally, shadow is easier to master, and makes one corrupt. To those who have light or shadow powers from the get-go, obtaining the opposite "element" can prove difficult, since the two powers tend to cancel each other out.
Stars generate light, which is a necessity for plants and thus all living things connected to them. They also give infrared light as a form of heat for our planet, though radiation and UV rays can serve as a subversion.
