It's the debate I've heard for a long time, which auctioning addon is "the best"? Well, first we need to understand that there is no "best" auctioning addon. It all is dependent upon what you want, what is best for you may not be the best for someone else. So, what are some of the options? And how do they stack up?
1. Auctioneer (release and beta versions can also be found at their website here)
Auctioneer is the original auction house replacement addon. It is a large suite of addons which all work together to help you watch the auction house, keep a database on prices, and help you find deals. Auctioneer is often used just show what an item's value is, however very few people unlock the full potential of auctioneer. Through the use of custom searches and batch posting and many other features auctioneer allows gold makers from those with a few copper to millions of gold to get more out of the auction house. Along with these advantages however, auctioneer comes with two major drawbacks, size and speed. With the whole suite installed, the auctioneer package has a large footprint. In addition, scanning and storing item data with auctioneer is slow to say the least. Because of these major drawbacks, many have decided to move onto other auction house replacement addons.
For those who want a smaller footprint but a few less features, there are two main choices I have used.
Auctionlite brings in clean tabs for buying and selling, as well as the ability to scan to store item price data. It supports tooltip information for item pricing and setting favorites for items you buy frequently That's it, if you want an extremely streamlined way to buy and sell goods on the auction house this here is your cup of tea.
For those who find auctioneer to large and auctionlite too little, your happy medium will probably be auctionator. Auctionator brings in all the basic functions from auctionlite as well as a few other features. It keeps a history of all items posted (also present in auctioneer) and allows you to make new posts based off previous prices. In addition it allows you to create shopping lists for more customized searching and purchasing and best of all the full auction house scan takes around 30 seconds in comparison to a 5-10 minute scan for auctioneer.
My personal preference? I run both auctioneer and auctionator on my gold making characters and just auctionator on the others. Are you using the default auction house window still? What other addons are do you like for the auction house? Stay tuned for some posts on my primary addon for making gold Trade Skill Master.