Alfred the Great was one of the most venerated rulers in British history, the only one to receive the title "The Great." He was born the fifth son of Aethulwulf, king of the obscure, semi-civilized Anglo-Saxon kingdom of Wessex (roughly, southwestern England from about Berkshire to Devon). He took the throne after the death of his father and brothers. During his reign, he held off the Viking invaders. He also was helpful in standardizing the laws and customs of the realm and encouraged learning. He even personally wrote commentaries on ancient literature. His small realm was to become the cornerstone of what is now Great Britain.
And what's he remembered for? Burning some cakes. Typical...
Back from the Brink: By the time Alfred came to power, Wessex was the last Anglo-Saxon kingdom left in England, the others having already been conquered by the Vikings, and he was forced to flee into the swamps and carry out a guerrilla campaign. By the time of his death, England was a united kingdom that would manage to resist the Vikings for another hundred years.
Badass Bureaucrat: Like most effective rulers he was this. Except he had too little rather than too much bureaucracy to deal with. In fact he practically had to invent his own bureaucracy.
Badass Family : Being an early Middle Ages royal family almost demands this as those who are not badass don't rule. However Alfred's family were unusual for this. His father and brothers were certainly not wusses and his son and his daughter(in a non-feminist society obviously) were badasses in their own right. His son and grandson went on to reclaim all of the territory the Vikings had conquered in England. Not to mention his grandson Athelstan who became the first true king of England. And of course The Kingdom Alfred's family founded went on to become The British Empire, so in a sense Alfred's family really did manage to Take Over the World.
Nearly all the kings of England have descended from Alfred.
Citadel City : One of the biggest projects of the later part of Alfred's reign was building a network of these. Many of them remain today though not as fortresses.
Courtroom Antics: He had to deal with these a lot. In one interesting example of the sort of off-the-cuff tribal justice of the time, two men were felling a tree when it landed on one man and killed him. The judgment was that the whole tree should go to the victim's family (wood was valuable property at the time). A verdict with a curious rustic common sense that one can understand to this day.
Didn't See That Coming: One for Alfred and then his Viking foes. When trying to impose a peace treaty in order to get some breathing space, Alfred realised that the usual oaths on the Christian God would mean little to those who worshipped the Norse Gods. To counter this, he got them to instead swear an oath on Thor, the Norse god of thunder and storms, only for them to break their oaths once more and send a fleet to attack Wessex. Things seemed bleak for Alfred until a sudden storm hit the Viking fleet, destroying it utterly and forcing them to agree to the peace treaty. Unexpected events all round.
Flaunting Your Fleets: He is given credit as the founder of the British Navy. Actually the truth is more complicated. Previous saxon rulers usually could call up a navy, usually by levying a fyrd from the owners in a manner similar to the way nobles(including the king) called on lesser nobles and sometimes peasantry to serve as warriors on land as part of a treaty of vassalship. However Alfred, in his reorganization of defenses, went to a great effort to ensure that he had a good supply of ships to do coastal patrol, carry troops and supplies for retaliatory expeditions, and similar things. The effectiveness of his fleet is debatable, but he was capable of catching and destroying some raiders with it on at least one occasion.
Folk Hero: According to legend, Alfred agreed to watch the cakes of a peasant woman as they cooked as a payment for Sacred Hospitality. When they burnt because of his inattention, he listened meekly while she berated him.
Foreshadowing: He made an attempt to build ships to pursue the Vikings and crewed them with mercenaries. This had limited success and was rather pitiful. But because of this, some credit him as the founder of the Royal Navy which was later to Take Over the Ocean.
Founder of the Kingdom: Other Anglo-Saxon kings had styled themselves King of England before, but Alfred was the first to make it really stick, and all subsequent English monarchs (except for The House of Normandy) are descended from him.
Kick the Son of a Bitch: The normal fate of a viking captured alive was to have his skin nailed to the church door. For some reason Saxons did not take kindly to having their children taken for slaves.
King Incognito: Would disguise himself as a minstrel and infiltrate Viking camps to learn their plans. The 'burnt cakes' story supposedly happened while he was in disguise for this purpose.
Magnetic Hero : This was back when government was barely above the Asskicking Equals Authority level and only kept there by strenuous effort even at times when there wasn't a great foreign invasion going on. Any king who wished to even survive under such circumstances was a Magnetic Hero.
Newer Than They Think: In his childhood, he visited Rome and was made a Consul by the pope. (Of course, there was no longer a Roman Republic/Empire for him to be Consul of, but the popes occasionally revived the now-useless title as an honor for visiting dignitaries.)
One of Us: Alfred was a nerd before the word existed. That did not stop him from being as ferocious a Warrior Prince as was seen in his time.
Overshadowed by Awesome: Tends to get overshadowed by King Arthur a lot, despite the seeming advantage of his existence being undeniably proven. Though this tends to apply only outside of the UK. He's still pretty beloved over there.
Real Men Love Jesus: Alfred was actually nominated for sainthood. He was turned down however because there were no miracles associated with him.
Alfred's law code has a lot of curious Values Dissonance that reflects a society that was in many ways a tribal one. For instance, a lot of it was about standardizing the wergild (blood price) for preventing feuds. The amount of wergild was rated according to the status or even (with a rather creepy sort of logic) the economic value of a given victim. Another curiousity is that the crown's protection was mainly over travellers. This in fact also has a weird sort of logic: people from nearby had their kin to look after them. In essence the laws were not new laws but the writing down and reconciling of old ones.
Alfred also demanded that every noble learn to read personally in vernacular. This not only helped found England's administrative system, which outlasted the Conquest, but perhaps helped lay a foundation for England's literary tradition.
The Sheriff: Not too dissimilar to the variety found in The Western, really, but the Western variety at least had a well-organized state backing it up, however far away. When sea-folk arrived it was The Sheriff 's job to gather a posse of peasants with Torches and Pitchforks.
The Storyteller: According to legend, he personally disguised himself as a bard and wandered into enemy camps to find information.
Unexpected Successor: Alfred's was his father's youngest son, with four older brothers. Three of those brothers inherited the throne before him, and all of them died within the space of roughly ten years, fighting against the Vikings.
Thomas Arne wrote an opera about the man which had been commissioned by Frederick, Prince of Wales. While not particularly famous, the finale of the opera is a charming little ditty called Rule Britannia.
The Saxon Stories by Bernard Cornwell, set during the Danish Invasions, shows Alfred as a major supporting character, who is fundamentally benevolent, but to the cynical, Danish-raised Warlord narrator, comes off as Lawful Stupid on occasion. It is notable, however, that he is one of the few said protagonist (grudgingly) has genuine respect for.
Alfred is a playable character in Crusader Kings as the King of Wessex and it is possible to reenact his task of defeating the vikings and found the Kingdom of England.