Ganon is always the same. Link is always the same. Zelda is always the same. Some say this makes the plotline always repetitive; I say it makes it all the more charming.
I agree with you there.
Link and Zelda may be different people in the games, but their appearance and trademark attitudes always remain great.
And there's an explanation for why Ganondorf permanently became the big pig we all know today...
Firstly, he gets sealed away in the Sacred Realm by the 7 sages. (OoT)
Next, he finds the Triforce there (probably after Link I and Zelda I died, which would mean their pieces were returned there) and makes a wish to turn it into the Dark World, which changes the appearance of anyone in it to reflect the feelings in their hearts. (ALTTP) Therefore, Ganondorf Dragmire becomes Ganon, a pig, because he is a greedy person.
Link II defeats Ganon in the Dark World and finds the Triforce there. While that is happening, a servant of Ganon's revives his fallen master with some of Link's blood spilt during the battle. You see, if a Triforce holder dies, blood from their killer can restore them. Ganon prepares on Death Mountain for his next plan. (TLoZ)
While he is there, he launches an attack on Hyrule with his army of monsters and kidnaps Zelda III, who shatters her Triforce piece into 8 pieces to prevent Ganon from gaining it.
Ganon takes control of Hyrule.
Link III finds Impa, who asks him to rescue Zelda and find the 8 pieces of the Triforce of Wisdom.
Link III does so, defeats Ganon, and peace is restored to Hyrule.
Until AoL, where Ganon's followers plan on killing Link III and reviving Ganon once again with Link's blood.
Link begins the quest to find the Triforce of Courage and awaken Zelda III from eternal sleep.
At the end of his journey, he faces the Thunderbird and his own shadow form (some fans speculate that this Ganon possessing the shadow), he defeats it and so on.
What is unconfirmed, though, is whether the Oracle games take place after this or not, Capcom appears to have made a royal screw-up of the plot by including OoT and MM characters here, which wouldn't fit.
Anyway, at the end of these games (if they're both linked together), a shell of Ganon's body is resurrected by Twinrova (?!) and easily defeated by Link III.
So, apparently, sometime before The Wind Waker, Ganondorf is brought back in whole form with Link III's blood.
Ganondorf is sealed with the flooded Hyrule, but finds he can transport himself to the Forsaken Fortress, and rules from there.
Since the bloodline of Link is dead, the Wind Waker Link is the start of a new bloodline. (However, he IS a reincarnation, that much we know)
Link finds Zelda's lost descendant (no spoilers from me here) and together defeat Ganondorf and turn him into stone. Hyrule is flooded again, with the Master Sword sealing Ganondorf away.
Just thought I'd share some wisdom out of boredom
