Dwarf Commoner is apparently the least-popular of the origins, but it's always been my favorite. The origin itself is super satisfying (kick a bunch of ass to shame the nobility! murder your mob boss!), as is the follow-through (betrayal by your best friend, finishing off your old gang).
I also like it because it totally justified my evil playthrough. Of course a lifelong criminal would feel that might makes right (side with the werewolves, templars) and have nothing but contempt for human religion and politics.
It's my third favorite after City Elf and Mage Elf, which might not seem like much but CE wins only by a hair and ME and DC are neck-in-neck.
I like it a great deal too. I tried the dwarf origins last and was floored by how amazing it was, and cursed myself for almost missing such amazing writing and role-playing content because of my conditioned prejudice against dwarf playthroughs. The Dwarf Commoner Origin and homecoming is amazing! I love how flexible the game lets you be with your relationship with your sister, your "best buddy" Leske, other dwarves around Orzammar, etc. And coming back to the place that called you less than manure in the dust after being away from a year, with your sister set to marry and with the baby of a noble, yourself changed from all the things you've done and seen outside of Orzammar, having the power to confront your past and change things there... incredible!
One of my best roleplay experiences also came from the DC Origin. I was originally going to use my DC as an evil playthrough too, since a lifetime of being treated like scum, having to look out for #1 (and Rica), and having to be aggressive to get anywhere would naturally make her ruthless on the surface, right? Well, wrong. My dwarf commoner surprised me by totally calming down once she made it to the surface. She no longer felt angry, aggressive, combative, or inclined to hurt people. She was rather calm and mellow and civil to everyone, and leaned toward the diplomatic outcomes instead of the skull-bashing ones. And I wondered why?
Then I realized she had no reason to be. She had cabin fever down in Orzammar; being trapped in a small cave filled with people who push everyone down, treat everyone like dust, and prevent each other and her specifically from being anything other than a criminal. Once she went to the surface where there's wide space, no caste system, people don't know her, there's opportunities, etc. She just saw no reason to be aggressive. If anything, she felt rather lost and out-of-place since her entire identity came from being an Orzammar casteless, and now she had to make a new identity in a strange land of strange people and things totally alien to her.
Then she went home again, where many old wounds got reopened and perceived friendships got torn open...
I could never have gotten that play experience with any other character, and really enjoyed it with my Dwarf Commoner. 