Let me be frank: Unless your backpack / purse / school books paid transit fares, DO NOT place them on the seat next to you. That seat should be available to actual paying customers who shouldn't have to plead with you to move your crap out of the way. That's right. I said it. Crap.
And while we're at it, I think it's fine that you may not wish to sit next to the window. But please do not, do not, do not then just sit in the aisle seat, thus blocking everyone else from accessing said window seat. If I have to stand because you refuse to move over or let me in, then you might as well place your backpack / purse / school books on that seat, because you're no better than the rest of 'em. (And just as inconsiderate.)
Wanna know what else annoys me about certain other transit riders? People who insist on having really loud conversations, either while on their cellphone or simply with the person sitting next to them. Nobody else on the bus cares what you did last night or if your kids are misbehaving or how lame you think your economics prof is, so bring down the volume and keep your conversations private.
And speaking of which ....if you're sitting next to me and trying to strike up a conversation while I'm reading or quietly staring out the window ....and if I don't make eye contact and only answer in mono-syllabic phrases such as "Yup", "Nope", or "I have a Taser", then please leave me alone. Everyone needs their quiet time to reflect and decompress from the day that was, and that time for me is while I'm on the bus. (And, yes, I know that "I have a Taser" is more than one syllable.)
I could go on about Mr. I'm-playing-my-iPod-this-loud-so you-can-all-hear-what-super-cool-music-I-listen-to or Mrs. Look-at-me-being-environmentally-saavy-and-riding-the-bus-with-my-kid-and-our-SUV-sized-stroller, but I might end up getting hate mail.
I guess the only thing then left to say is this: If you're ever in the position of riding ETS, just be considerate and respectful of your fellow transit riders. None of us really want to be there, so please try not to make it any worse with your obnoxious behaviour.
Oh, and for the record, I do applaud moms who are green enough to ride the bus, but is the excessively super-sized stroller really necessary? C'mon, ladies, it takes up five seats! Perhaps it's time to down-size the stroller, n'est pas?