I love me some Origins. What can I say?
The fact that your origin story -matters- and can actually color your view of the game story is an interesting thing.
I played as a Human Noble, so things like the Dwarven culture seemed... well... I didn't really clue in how unique and -different- it was from the norm. Yeah, they care about honor, and there's some politics and there's a downtrodden class, but nothing really stood out...
...and then I played the Dwarf Noble story. Suddenly Ozrammar seemed like a very -very- evil place, a place of constant stagnant tragedy, of danger and of intrigue that made the Couslands' troubles seem like a walk through caketown. Also, Gorim suddenly had some importance other than the Denerim 'DWARVEN CRAFTS!' merchants.
Yeah, it plays with some of the tropes, woodsy elves, tradition-based dwarves, but damn if it doesn't start to deconstruct them and start going in totally different, morally grey roads with them. There's no good guys in Dragon Age: Origins. There's just the threat of annihilation and an ancient order who only exist to do Whatever It Takes to defeat that annihiliation.
Some of the game choices -really- challenge the player in terms of moral outcomes. It's -hard- to be a total goody twoshoes, and the game does NOT reward you for being good, or for being evil, or for being neutral in the same sense that KoTOR does. Does your morality matter? Yes, but not in the sense of "I AM GOOD HUZZAH" but more "I regret doing this thing, but it must be done or else everyone dies."
In the words of Duncan "I am sorry." And yet, he does what must be done, and that sets the tone for the -entirety- of your quest, where you may do acts ranging from demon-worship, to genocide, to exorcism, and sometimes all at the same time.
There's humor in it, but it's not the same style of humor as HK-47 or Minsc. It's a more intellegent, dry wit that pervades the game. It doesn't feel over the top, but it's a lot more subtle and some players never really catch the true charm of it. I for one -love- the dialogs that randomly break out between characters. Alistair and Morrigan's naturally foiling each other, Zevran hitting on -everyone-, Lelliana's stories as you approach items of interest... it's a rich tapestry, and you're trading in 'GO FOR THE EYES BOO' one liners for more substance and texture in the dialog.