As far away as possible. Then usually I'll put my gigantic purse right next to me so no one gets in my space.

I prefer to have plenty of space between us - at least 1 empty seat. If there's no choice, and it's the difference between getting home or not - I'll sit anywhere!

I usually try to keep at least a seat or a couple feet's distance if I can. I hate it when people come and sit right up next to me if there are other places available, though.

I don't do public transportation but even like going to theme parks an their trams and what not I try to keep at least one open seat between us

when we use the train, I try to sit as far away from strangers as I can

I usually don't like sitting next to strangers.

I try and give space when I can. I don't use public transportation a lot, but when I'm on the local subway (which is mostly above ground, but anyway) I try and give a wide berth. But if it's tight I'll scoot in.

I leave as much personal space as possible.

I don't like to be in their 'bubble', nor do I want them in mine

As far away as possible, within reason.

Far...far away, I tend to avoid other humans as much as possible because I'd rather not hear what they may or may not be saying about me.
I suppose it could be called slightly paranoid to just assume people are going to make fun of you, but in my experience it happens a lot (mostly around teenagers or people around my age, haven't had it happen with older adults or elderly ones either yet) so I'd rather avoid it.

I do try to be friendly and polite if I'm forced to socialize or sit close to someone for whatever reason though, even if I have to fake being nice so I don't come off as a frigid bitch (I'm a very quiet person that likes to keep to myself and some people seem to mistake that as me being a grouch sometimes).

I keep my distance.

In their lap, if they'll let me.

Okay, maybe not so much. lol I'll try to leave at least a seat between us but, if it's crowded, I don't have a problem plopping down right next to them.

I keep my distance.

I sit as far away from them as possible... especially if they appear annoying.

As far away as possible, yep.

I definitely prefer to sit as far away as possible!