This is my opinion, of course, and you are allowed to disagree with it, but I've been playing video games longer than some people on this site have been alive, so I feel that I have a small degree of knowledge on the subject.  So here it goes....

A real (well-rounded) gamer:

1.)  Does not only play first-person shooters.  You can talk to me about how many headshots, total kills, nuclear bombs called in, prestiges, stuck grenades, and whatever else you've had in whatever game you choose to play, but a FPS fanatic does not a well-rounded gamer make.  If all you do is play Modern Warfare 2 for hours, days, weeks, and months continuously, I don't consider you a gamer, I consider you a Modern Warfarer.  You need to branch out into the other fantastic games that are out there (though I know your selection for non-FPS games is quite limited if you have a 360). 

2.)  Considers the Wii to be a legitimate gaming device.  While I am VERY well aware of all the garbage that is available for this system, there are a few diamonds in the rough, so to speak.  SSBB is a very good game, and I have had hours of fun with it, but I also enjoyed Super Mario Galaxy, Metroid Prime 3, and a few other games that are good.  While you may have to wait a bit longer, you can find good games for this system.  That goes without even mentioning all the Virtual Console titles that are available.  While it has not done nearly as well as it should in the quality game department, the Wii does have something fun to offer.  Which leads to my next point...

3.)  Will play casual games because they are fun, too.  Just because you're not shooting someone in the face or cutting someone in half does not mean the game is not fun.  You can enjoy yourself on a game without killing someone.  Trust me, I've done it.  There are games out there that can be fun to play with your non-gaming parents.  I think that Boom Blox is one of the best games ever made, and I base that upon the amount of fun I have had playing it.  While I agree that I usually have more fun in my one-player games where I might kill a person or two, there is other fun to be found.  So stop scoffing at me when I tell you I'm going home to play Mario Kart.

4.)  Will give titles of every ESRB rating a chance.  Dear 15-year old gamer:  I play Mario, and it is fun.  I'm sorry that he doesn't kill anyone and that his lands are more than just brown and gray.  However, being a very fun, jumpy, crazy Italian plumber does not make him gay.  It makes him awesome.  :)  This kinda goes with the rule above.  Sometimes, an E-rated game is great.  Just because it might be meant for a younger audience does not mean it is not fun.

5.)  Will give games with a bad review a chance.  Occasionally, I get excited about games in previews of magazines, and then am slightly disappointed when they receive poor reviews.  However, if I really want to, I will buy that game, and I will play it.  Am I wrong to do so?  Sometimes, yes.  However, I have found games that I really like by doing this (Mirror's Edge).  This rule kinda goes with another, which is to take a chance on a game that you've never heard of when it gets  good reviews.  I did this with Katamari Damacy, and I really enjoyed it. 

There are many more ideas I had for this, but I don't want to make a super-long blog that no one will read.  If you have more ideas for rules, feel free to add them.  If you disagree with some rules, tell me why.  I might make a second round of this if it is desired.  Happy gaming!