Older people want to be as close to the exits as possible so they can get off without having to push past fifteen people in the aisle.
Beyond that... Dunno.
You whippersnappers are playing that dadgum music too damn loud in the back.
My choice of seat depends on who looks like they don't believe in the Evil Bath Process.
I try to stay downwind.
However, if after I am seated a crazy boards the bus,they will undoubtedly sit next to me. And discuss crazy until I get off the bus three stops before my own just to escape the funk.
There is no escaping crazy.
Funny, i get nearly the same seating pattern at my church...
(PS: any man with half a brain knows the best seat is ALWAYS next to the prettiest girl.)
What about standing versus sitting? I usally start off a trip standing if the bus is crowded. I don't mind. I'm a young-ish, healthy-ish man with all my limbs in decent working order. It bugs me when kids don't get up to let their elders sit down. If a kid in a big, puffy arctic explorer coat is sitting in an aisle seat chewing on a McDonald's straw, they just swing their legs to the aisle and make the woman climb over them to get to the window seat.
I don't ride buses. Only Democrats ride buses...