Aion Online with over 1 million units sold.
But with a game this popular you are also sure to see a large amount of bots. NCsoft is craking down and has banned 16,000 accounts. This should improve the gameplay for others at least for awhile.
Accounts were banned for use of third party software also known as botting, buying or selling gold, spamming, sharing of accounts, purchasing or selling accounts, power leveling, and any other violations of the terms of service.
