Love these. For me, those would be conversation starters (depending on your affect at the time of delivery), not enders. Same for me, being humorous usually leads to a long conversation, even when I am being a bit blunt.

If someone askes an invasive question I raise an eyebrow and say, "Why do you ask?" Then I change the subject before they can reply.

However, when some rude, crude, creepy dude on this website asked a horrifyingly sexual question about my being transmale I immediately flagged him, and his post disappeared. I wish getting rid of jerks in real life was that easy..

As a transwoman I deal with shit all day long..90% from men and about 10% from women. Depending on who says what I either say "More of a woman than you'll ever have" (men).women on the hand say the "You'll NEVER be a Real Woman" to which I quip "Funny I was think the same about you..Dear"

Whenever I witness someone make a particularly racist or sexist joke I pretend I don't get it and ask them to explain it. Things tend to get awkward real fast after that.

I like to make people who make things awkward even more awkward, if not downright vile. I see your invasive question and raise you. Your move, chatty kathy/karl!

When you own dogs you get people who just want to tell you how bigger and better there dog is for some reason without even asking. a bloke looked at my alsation once and said "nice dog but mine is twice as big" I responded by saying "wow 56" at the shoulder, id love to see an alsation that big" or they say its just a dog and I say your just a human.

you're funny! one i say that nobody gets is when somebody says "dam it's windy"... i say "it's not wednesday, it's (whatever day it is)"

Questioner: “Do you believe in God?”
Responder: “Which one?”

I think both jokes and blunt refusals work.
It depends on my mood which I'll use.

Humor kind of defuses it a bit. If that doesn't work, I've had to resort to blunt assertiveness. If you have to get to that level, it doesn't matter how the other person takes it.

Only when it is at their expense!

Humor always works. Anything to divert the conversation works. Of course, the atom bomb of comebacks is to start talking about your health problems. They will quickly find an excuse to leave.