From what I have read and experienced, dueling, while fun, lacks the fairness and rewards many of us had hoped to see in D3's PvP. My idea has both of these, and here's how it works. Players will login to the game as usual and see a button for "Player vs. Player" beneath Public Games. If they feel like PvP'ing, they will click the button and a menu will pop up. The menu has 3 categories of gear quality to choose from: magic, rare, and legendary. Say that a player chooses 'magic'. They will then be put into a queue to match up with other players who chose the same category. When 4 players are found, all will appear (with their previously equipped gear in stash) in an intermediary area with an NPC vendor called "The Lanista". The heroes will then have 1 minute to equip themselves with the chosen quality of gear sold by the vendor. The items will be random affix, as if dropped from a monster, and cost in-game gold. When the time is up, the players will appear in an arena to fight with whatever gear they have managed to equip themselves with.
1st place will win a substantial amount of gold that will exceed what they probably spent on their gear.
2nd place will win back the gold they spent on their gear.
3rd and 4th place get no reward.
These matches open themselves up to many possibilities when it comes to player rankings. For example, there could be a list of the top 1st-placing characters when the Player vs. Player menu opens.
I believe that this system would offer players a chance to test their skills and have fun, while feeling rewarded for playing. I also believe that this is the best way to have balanced and fair PvP while still utilizing Diablo's RNG loot system. Please feel free to comment, criticize, or offer suggestions. I very much want this game to have a "real" PvP system, and have since day 1. Your ideas are also welcome. Thanks for reading!