I recently just played Dragon Age origins and Dragon Age II for the first time.
These were the best:
Zevran - Unlike Morrigan, Zevran is actually likable in how evil he is. He handles everything with a flippant flair that makes it seem like he's less a monster or a killer and more just....excitable. He's simply the most fun to talk to of everyone in DAO, even if Sten is more interesting to talk to. Zevran is the ultimate bro - albeit a very sexy bro I slept with gladly. But it's not all skin deep. You can sleep with him but if you start to actually get close to him, he holds off on the sex because he wants to make sure it's something more. His life, no matter how glamorous he tries to make it, has clearly hurt him in many, many ways and helping re-establish his ability to form meaningful bonds with other people is a very warm and satisfying thing.
Merrill - I romanced her on my second playthrough. Friendmance, if you are wondering which one. I was initially put off by the face tattoos but if you just talk to Merrill, it's impossible to not love her.
Merrill: Your armor is very shiny, Sebastian. Doesn't that make you an easier target?
Sebastian: The Light of the Maker is my armor, Merrill. I am not afraid.
Merrill: Maybe you could ask Him to make His Light less shiny? Then you wouldn't need as much armor.
Perhaps I just have a weakness for the "cute bubbly one" because I also fell in love with Leliana in DAO. But Merrill has an earnestness about her that you can't help but find endearing. She's doing the best she can, in spite of being raised by a bunch of superstitious racists. They deserved to die. Now she can live a more happy life with Hawke, someone who truly appreciates her.