This leaderboard shows the most active publishers and community managers in the games industry. Whilst mostly aimed at the UK, there are a few global ones in there.
About the weighted index
Scoring is based on tweets, mentions, retweets and Klout. At the moment the exact calculations are a work in progress. ReTweets and Mentions are worth more than Tweets and Klout. Also, there is a calculation that checks how close your number of tweets to mentions is. The closer together they are, the LOWER the score - which is good as it shows that you are neither a pure broadcaster or a lurker. The number can be distractingly large (in the 10's of thousands!), due to limitations in the formula I can use!