Honestly it doesn't really matter to me. Depending on whether it's on the top or bottom I'll just put my phone in my pocket to make it point upward when I use it. I tend to use Bluetooth anyway most of the time, so the headphone jack is mostly there as backup and for connecting other audio devices at parties etc.

I do not care about having a headphone jack, but it would be nice to have the charging port on top; it's more out of the way for me.

The side of the phone.

Bottom.

Top. So it can sit in my cup holder with the map up proper.

Top

I don't think I've seen one at the top..

I'd say bottom because I'd rather not have the cord coming towards me, rather than away, when I'm using the phone. Also it seems more ergonomic for me to put my phone in my pocket with the top pointed down rather than up.

My phone has it in the upper top right, and I like it there.