If I was choosing someone, I'd want it to be someone who is very high up in rankings (ie someone respected, skilled, and knowledgeable), who contributes to both the game and the forum in some way, someone who helps others with advice and pointers, and someone who - if they were gone - would be a loss to the game and community.
Speaking for myself, looking at my own words above, Bluemax and wig come to mind - they both contribute, both have helped me in different ways with advice and pointers, and both would create a feeling of loss if either was gone. But its very hard to choose isn't it? We can't all be moderators or hold spots in the top 10, but don't have to if we want to contribute. This is a great community of players, and I've made friends here that I communicate with outside of the game and forum, and there are VERY few players on here that aren't willing to help or contribute as best they can.
Tough choice boys and girls!