It's easy to say 'Gaming Culture' but i think this is to generalised, because there are so many different experiences avalible and with them come different people and different behaviour.
For example you have your MMORPGs, where communites are created and people will become submersed into a virtual world. On the other hand you have FPS', where teams and clans are formed and compete in a more competative nature.
There is also big money at stake with the major gaming leagues, where people and teams (depending on the game) will compete for vast amounts of money. The gaming leagues will show the greatest players and teams, but perhaps they don't have the same sense of community that an MMO game would have.
My experiences within a game community aren't that extensive but I was once a member of a clan, and a bloody good one at that. Not good as in talent-wise but because we were a good team. The game was Socom: U.S. Navy Seals on the PS2. It was more of a casual thing for most of us, we would usually have a clan match once a week and then play together whenever we were online. Like I said, it was the people in the clan who made it. One guy, Taz, who was a bit of a loud mouth would ALWAYS blame laggers and would get really worked up sometimes (much to our amusement). We were all quite laid back and never took it to seriously, but when the match came around we would co-ordinate and used tactics to work well as a team.
It was a great game with a solid online mode, which proved to be a great foundation for (TUE) - The Ultimate Elite (ok so everyone thought it stood for Tuesday, but the name makes us sound good doesn't it?)