Im thourghly suprised by the responses this thread has recieved, on both topics and all oppinions. I appriciate all the oppinions expressed here, even though I agree with few of them.
That being said I would like to elaborate on my situation.
First off all the players are under 21. Most are 16 and 17, at what I like to refer to as "That Age". This doesn't mean they are all immeture and childish, BUT they do tend to disreguard other's fealings and just say what ever they want. And frankly from time to time they can be downright rude or even cruel. I've seen groups of 30 and 40 yr olds with less maturity than the group I am running but not as consistantly as this group.
The two that don't get along well are kind of a problem in game and out of game. One is a VERY good friend of mine while the other is my Brother-In-Law. It puts me in a hard place often. Mostly they don't get along due to the friend picking on the BIL. Another consistant problem is that there is a pair of siblings in the group (older sister, younger brother). So theres alotta nit picking and bickering, but it usually is quashed with me telling them "Save it for the ride home".
My game sessions run for 8 to 10 hrs due to the fact that we play only twice a month. This being said, EVERYONE gets a lil cranky after spending 10 hrs at a table with eachother. We take breaks often for food and drinks and varied reasons. Especially when I order pizza, theres about a 30 min break while everyone mobs the kitchen. But for the most part it stays civil I have yet to have a serious problem.
To reply to some of the comments: Not all of us are good friends so its not like we ALL know eachother personally outside of gaming. Some of the people in the group meet for games and get along at the table just to enjoy a game of DnD. We aren't all best of buddies outside the game table and not everyone hangs out when not gaming. This is mostly due to the same reason we only meet twice a month. Also, some of us are still learning the game and some are Pros at it. Some of us are quiet and reserved and some are loud and in-your-face. Some are ubber conservetive while others are the ultimate free thinkers.
With all of this being said, I find that, WITH THIS GROUP, as a DM, I have to have a firm hand and an iron rule so that every one can have fun and get along fair. Its worked well so far and despite me having to play judge often every one has a blast and there are plenty of laughs and enjoyment to be shared at my game table.
P.S. I can't say that in the past I haven't tolerated bigotry at the game table. This is something I personally feal ashamed of, however, I have learned my lesson and Bigotry of any kind is automatic grounds for expulsion and non re-additance to my game table. Period!