Here are my ruthlessly subjective winners for the most honest act in Fallout: New Vegas that made your heart hurt.
Of the 200+ entries, here are the winners followed by a lot of honorable mentions.
Next contest for Old World Blues should be up on Twitter soon. It'll probably involve experiments. Or captions. Or something blue-sy.
Warning: Spoilers below.
Created my account just to answer. Though it has been said before it must be the Hanlon affair, truly morally ambiguous.
Realised I should probably expand. I chose to turn Hanlon in, and his speech touched me and I regretted my actions.
After that I felt the consequences of my actions greater than ever before. A good man died because of me, and I knew it.
Runner-Up (Still gets a shirt) =============
David_Vanek When is saw hostile animals i didn't kill them i just ran away because im afraid they'll get extinct.
Honorable Mentions ============
razorangelwings The hardest honest act was convincing Lily to take her medication, and forget her grandchildren
VLVX telling Davison his master is just an inanimate Brahmin skull.
(Humor Bonus) Digitalvitriol It was tough to decide whether or not to carpet-bomb Camp Golf with mini-nukes, but drinking made it easier.
(Because I agree) Stevens4932 Healing Snuffles Leg was pretty cute so that made my heart hurt.
tittlekid Found Mr Cuddles for that Boomer kid... then took it home instead to decorate my presidential suite. Sorry, kid.
sirboulevard Activating Archimedes instead of redirecting power to help everyone. I chose a death ray over helping us all.
(Agree on coolness) Ben_Parsell When Benny gave me advice on how to carry on his legacy even though he knew he was getting a machete in the neck.
Delixe I stole everything in Doc Mitchells' house. I did it right in front of him so I was honest about it.
darnellmeghan Ripping Melody's teddy bear in half just to gain influence in the Legion.
nuclearmission Shooting down the men in Nipton off their crucifixes after the Legion came through. Almost cried, but it was just, right?