The other day while playing Modern Warfare 2, I realized something.  Most of the time, the victors manage a silent magnanimous.  However, the losers typically criticize the victors method of winning.  Even if it's an honest win, those who you defeated will tell you whatever method you used is wrong.  Nevermind the fact that you beat the other guys: you still did something wrong!  A "better" weapon, a more strategic class or team, simply being a better shot, or the usual scapegoat: camping.

Ok, let's look at some things that could give you an edge.

The Better Weapon

I am going to immediately discredit this one by defending the game's developer.  No matter what game you play, a lot of development, quality testing and adjustments go into a weapon's attributes.  They all have their pros and cons but are generally level on the playing field.  Do weapon perks give you an edge?  Sure, but they also come with their limits.  Now, to play devil's advocate against Infinity Ward: the 1887 shoots ridiculously far for a shotgun.  Really, cut it down some.

Better Class

Once again, the classes are pretty level as far as the playing field goes.  Each one has its pros and cons.  Bling may give someone a edge over a guy with a red dogt sight and no silencer, but that guy could easily add Scavenger so he could spray bullets a little more liberally.  Cold Blooded will save you from NPC choppers and harriers, but Stopping Power Pro will help you knock them out of the sky quicker.

Skill

Why would you pick on someone for being better than you?  You're just opening up your own anger for not being as good.  Someone who puts lots of hours into playing and gets good at it is just getting what they put in to it.  "Oh, the only reason you guys won that round of Headquarters is because your team knew you should focus capturing before killing!"  Idiots.

Camping

Ok, eventually you can get any weapon with any attachment in the game, you can learn strategy.  So you boil it all down to this, what's left?  Perhaps you realize that the first instinct that comes to mind when you play a first-person shooter is to run around an look for things to shoot.  Well, if there's enough people running around, then one is bound to run by you.  Especially when you find a swell spot that has a lot of traffic.  You can just sit back and wait for them - or camp!  But to camp, you need to know a map well: where people will go and where the cover is and how to use it.  This takes patience and plenty of research.  It's really a skill, something you need to excel at anything else you do.

But alas, no matter what you or I do to win a game, even if it's dumb luck, it's still the wrong thing to do in the eyes of those you defeat.  You can just bask in their pain, or tell them what I say, "Go ahead and talk [crap], we still won."