OK, I hate riding on the bus to get to school. I am always the last one to get on, leaving no room on the bus to sit, and there is always a collection of characters who frighten me. All of the genres of people listed below are all in 7th Grade or lower.

Group One: The Stereotypical Fat Children

OK, being an overweight person myself, I can understand the ridicule these children goes through. But unlike myself, these kids commit themselves to making them look as FAT as possible. They are obese (much more than I), smart-assed, and quite retarded. There are so many accounts I have had with these kids, I could use an entire news post about it. But, I have another genre to go through, so I won't.
On the first day of school, I saw this group of kids (who are all in 5th grade). All of them had fatty faces, and chubby fingers. Since I had to sit next to one of them, I had the disturbing encounter. The kid next to me took out a "family-sized" bag of Doritos, and just munched away on them in the most annoying way possible. You know. People open their mouths slowly, making you smell the saliva-tortilla chip slop in their mouth, also forcing to to see the chunks of spit and crumbs drool out of their mouth? Yeah, That kind. Anyway, in the 15 minute trip to the school, he finished off the whole bag of Doritos, and three Hershey bars. Bleh. But WAIT! There's more.
These fellows like to shout obscenities into the air, not taking their young age into recognition. While they play their PSP's (which they say is so cool, and are a "fuckload" better than any other system ever made. Direct quote.) They like to say words such as "fuck", "ass", "bitch", and other obscenities. Today on the bus, they were discussing, jokingly, how they might have a disease which make you not filter your speech, obviously Tourette's Syndrome. After a few minutes of discussion, which I could not here, we hear a single phrase come out of the fattest of them all.
"Hey everyone! I can't control what I say! I have AIDS!". Sigh.

Group Two: The Gay Kid

Everyone knows the gay kid. He's in your school. In your neighborhood. And, if you are like me, on your school bus. This is the kid that sits alone, and everyone is willing to sit three-in-a-seat, just to avoid him. When you are unlucky enough to sit with this 7th grader, you know the rest of your day is going to be fucking sucked down the toilet.
If you are a girl, you have nothing to fret; he never even speaks when he needs to sit with a female. It's like poison to him. He actually curls up into a ball if a person of the opposite sex sits with him. But, if you are a guy, you are in for one hell of a 15 minutes. And I don't mean that in a good way. First off, as you sit down with him, he stares at you. Now, some people may say, "Hey! You're just over reacting." Well, the thing is, whilst he stares at you, he smiles, and rubs his crotch. I want to puke right now. I've been violated by a twelve year old. How sad is that.
He continues to say that he's not gay. But, whenever he's on his PSP (see above, it seems to be the next best thing since sliced bread on our bus), his hand slips into his pants. I don't even want to continue typing about this topic. >:(

EDIT: 12-21-07
Group Three: The Legion of Gum Chewing 5th Graders
You can never take out a pack of Trident or 5 on my bus. Why? Because they will get you. See, whenever you take out a pack a gum, and just make the tiniest sound, they pounce on you. Who are they? The 5th graders. And this includes the Fat Kids from Group One. You know in horror movies, where the villian slips his head around a corner ever so slowly, only to attack it's unaware victim? Exactly like that. They will hear it, and as soon as they got you in their sight, they scream at you like banshees; "I WANT A PIECE OF GUM!!!" And if you don't, the kid will cry, and make the bus driver order you to give him one. Then, all the other 5th graders jump the bandwagon and want gum. By the time you get all of them to shut the fuck up, you realize that they have taken an entire pack of gum, INCLUDING THE ONE STICK YOU WERE PLANNING TO PUT IN YOUR MOUTH IN THE FIRST PLACE! And once you are all done, the whiniest kid starts doing that "cry-baby I-DIDNT-GET-A-PIECE" sob. And you just want to shoot yourself , because you are now out 20 pieces of gum. And that was supposed to last you a week, and it was gone before you even reached school on Monday.

Edit: 01-03-08
Other Surroundings: The Radio

Now, this isn't about the kids on my bus, but the surroundings. They can be quite the hassle, as well.
We have a radio installed on our bus. Great, huh? We can listen to music, and be nice and calm, right? Wrong. Just the opposite. We have two music genres to listen to; heavy metal, or karaoke. When we get to listen to karaoke music, it is allways some shitty singer, singing a terrible country song. It sounds more like a cow that just got run over by 10 semis than music. But, the bus driver loves it, and we need to listen to it as well. Then, we got heavy metal, which is always some third-rate band no one has ever heard of. We always pick up the greatest radio stations, huh? Anyway, the music is just way too loud. I mean, mind-numbingly loud. I can't even concentrate on the book I'm reading or the game I'm playing long enough to get some effort in. And, the kids on the bus don't even listen to it. They yell LOUDER than the music to get their voice across the dense fog of sounds. That makes a terrible migraine brew within my head. Once we reach the High School, I get out of the bus as quickly as I can, because there is a river of noise following me from behind. I wish that we can listen to good music, from better bands. Hell, even Mozart in the mornings would feel better.

This is one reason why I wish the driving age was reduced to 14. I deal with this shit every single day, and I am getting sick and fucking tired with it. Anyone else have one of these groups on their bus?