I've always disliked the term "true gamer". Really, if one plays games, they are technically a gamer. I don't think it's a matter of skill, or time clocked per week, or anything. I suppose it could be argued that people who spent lots of time and money on it are more serious about the hobby, and can be considered "hardcore", or whatever. As long as it isn't used as a derrogatory word against casual games, it really doesn't matter to me.