I think City Elf is the most powerful and emotional Origin out of them all and is certainly a favourite of mine. I mean look at all the stuff they go through, how could anyone cope with going through all that?
Dalish Elf is ok at the start. It is interesting to find out about the Dalish elves and such but it is rather simple to me. It does become sad later on and especially when Duncan recruits you. But that moment later on in the game with 'you know who'...

it just completes the Origin for me.
Dwarf Noble I really like with all of its politcal overtones and sibling rivalries. Makes you feel like you really are in a place of power with everyone either admiring you or scheming against you.
Dwarf Commoner is supposed to be the opposite to Dwarf Noble, but they are quite similar in the way that they show how Orzammar's politics and traditions are run. It shows how messed up people's lives are in their rejected lives. Your family and yourself are so messed up and neck deep in such despicable things that it's the only way your able to survive.
Magi origin are all about trust and betrayal. All the Origins are about trust and/or betrayal but the Magi origin is almost entirely based around it. But even with this whole trust thing it seems more dull to me compared to other Origins.
Human Noble is rather simple compared to other origins but it is just as sad as some of them. It can have real powerful effects later on in the game so later on it becomes a favourite. (STAB HIM

)
All in all my fav list of Origins is like this.
1) City Elf
2) Dwarf Noble
3) Dwarf Commoner
4) Human Noble (but as said it is one of my favourites, this is just for beginning.)
5) Dalish Elf
6) Magi
I like them all so it's real hard to choose between them, but C.E just wins it for me. I did like Magi but it just doesn't compare to the other Origins I feel.