Damage Dealt To Champions seems to be weighed as "the golden standard" for how well a player does in a game. This really is an inaccurate way to look at exactly how strong a specific player was, and I think there should be another statistic added which factors in a players build to show "potential" strength.
I often see other players telling me I'm useless because I dealt less damage, when I'm a Jungler and didn't spend my entire first half of the game trading back and forth with enemy champions. Last game I even had 6,000 more gold and 5 items, compared to another player's 2 and a half items and they were still trying to tell me that I was useless because they did a little more damage than me [to champions]. It feels really bad to be weighted in such a manner knowing that (in that particular case) I was likely the strongest and most impactful member of my team.
At any rate, I'm not quite certain how it could be implemented, but I wish there were some type of "power rating" which gives a score on how strong you were at the end of the game. Not something that's just based purely on damage dealt, but also your items and other statistics, combined into one single rating. This would really deter those people who have inflated egos just because they did a bit more damage than someone else.