I really, REALLY try to make a good character, heck, I even sometimes plan to be the 'bad guy.'
Sadly, in-game, I fall torwards neither. In F3, I planned to be the goody-two-shoes, yet ended up being a degenerate drinking gunslinger with a penchent for pistols, sniper rifles, and caps. Precious, precious caps.
I think, in Vegas, its gonna fall down much the same way. A pistol/rifle-slinging hard-drinking, gambling son of a gun, who's morals are dictated by whomever pays the most.
What? You NCR guys got nothin' but fresh water, and a hopeful smile? Alrighty then, off to join the legion.
I also freely admit to letting other people do the fighting for me. (Would hate to take a bullet, when I could be scavenging your/his corpse. Nothing personal.)
I do seem to remember being able to capture slaves and sell them in F3, although that could have been a mod. Good caps! (I think I felt bad afterwords. Almost. Maybe.)
So yeah. Although, I did choose the 'good' ..
ending. So I guess that speaks for itself.