This is the kind of thing that can be answered by looking at the online Compendium, which you can search even without a DDI subscription. By searching Avenger and selecting Paragon Paths, a list is generated that includes the names, prerequisites, and sources. If any of them were from multiple sources then you wouldn't be able to go further without a subscription, but as it happens, none of them are. The full list is:
Dervish of Dawn, Favored Soul, Watchful Shepherd, Relentless Slayer, Serene Initiate, and Weapon of Fortune, all from Divine Power, and all with either Avenger or Avenger and Oath of Enmity Power prerequisites (since both Avenger Multiclass feats supply Oath of Enmity, that's functionally the same thing- any pure, hybrid, or multiclass Avenger can use these).
Hammer of Justice, Unveiled Visage, and Oathsworn, all from PHB2 and either Avenger or Avenger + Oath of Enmity power prerequisites.
Agent of the Unbroken Circle from Dragon 387, Avenger + OOE.
Watcher of Vengeance, Avenger + Trained in Insight or Perception, Dragon 377.
Zealous Assassin, Avenger + Trained in Stealth, PHB2.
Ardent Champion, requires Censure of Pursuit, Divine Power.
Dread Imperator, requires Censure of Unity, Divine Power.
Covenant Agent, requires Avenger + Assassin, Dragon 386.
Mighty Judge, requires Half-Orc and Censure of Pursuit (and the OOE class feature, but you can't get a Censure without the class feature), Dragon 386.
This list does not include generic Divine Paragon Paths- there are plenty of things that require a Divine power source class, and often worshiping a specific deity. But my read of your question was looking for things that were specific to Avengers.