Helping Freeside. Really wish it was more developed story-wise, because a team up of Julie Farkas and The King would be a Vegas force to reckon with. The Thorn (or, more to the point, Red Lucy) is also awesome. The final part of Bleed Me Dry on VH/HC is beyond glorious. Even more so if you do it with "vanilla" weaponry. No special OP uniques.

Above all these though, is turning the tumorous contents of Eddie's skull into abstract wall art with a 12.7mm pistol. "Mighty Caesar" indeed. The entire one-sided annihilation of all the forces at the fort just added to the moment.

"Retri-" BOOM HEADSHOT

Rendering unto Caesar :bowdown:
He is such a wise many thou shall do well to listen to him.

Talking to House is also good.
Blow Kimball up with C4 strapped to the idiot NCR soldiers hat.

Kimball - "His actions are a beacon to all of us who stand here today in tribute to his valor. Private First Class Jeremy Watson, on behalf of the senate and people of the New California Republic, it is my honor to present you with the St....."
*BOOOOOOM*
Courier - "http://www.youtube.com/watch?v=aIrhVo1WA78"

Finding that bright Orange feral ghoul "Overseer" in one of the vault for the first time, that was quite cool.

I could walk for minutes literally in Fallout 3 and not encounter an enemy until some randomly spawning thing came to get you (like a Deathclaw outside Grayditch?) . You can't do that in New Vegas.