The Gen Con event listing website at gencon.highprogrammer.com now has 2016 events up!
I'm proud of the ability to browse by category and game, or by hosting group or GM. But I think the best part is the search capabilities. If you want a role-playing game that starts no earlier than 10pm on Thursday, but is done by midnight, doesn't allow anyone younger than 13, and doesn't require any experience my system can find it. (At the moment, that's 4 different games.)
The data doesn't quite match what you'll find on the official site. As part of loading the data, I clean up common typoes, misspellings, and a few things that irritate me. I try to match what the publisher calls a game, although I don't respect gratuitous ALL CAPS.
The bottom of every page on that site has contact information if you have questions, suggestions, or run into report bugs. You can also reply here.
Because I'm not the official source, my data lags behind, typically by a few hours.
(Thanks to the person who poked me on Twitter; I forgot the data was being released today. :-) )