Having played through and finished the game and it's DLC's thoroughly, several times and with each voice, I can give you my brief opinion on them.
The British Male voice - Harry Hadden-Paton: Personally I really liked it and it fits an elf or human character really well. However in some situations it was quite emotionless, compared to the other voices, much like Mark Meer's voice compared to Hale's in Mass Effect! But on a whole, I really liked it. He is quite good at delivering the diplomatic or sarcastic/jokey lines.
The American Male voice - Jon Curry: Now I have to say this one is my absolute favourite. The level of emotion in his deliverance is superb and he gives the character so much personality. He was good at being diplomatic, sarcastic and aggressive. I liked every response I chose with this voice.
The American Female voice - Sumalee Montano: It took a while before I used this voice for one of my characters, but I have recently completed the game with this voice for my female dwarf and I was very impressed. It was better than I expected, as I didn't like how she sounded in the prologue, but throughout the game she just got better and better until I fell in love with her voice.
The British Female voice - Alix Wilton Regan: I'm sorry to say this, but I found this one to be my least favourite, which really surprised me, as before the game was released I was really excited that she was one of the voices for the female Inquisitor. I loved her voice in other Dragon Ages and in Mass Effect 3, but playing an Inquisitor with her voice, I just didn't warm to it. A lot of the time it sounded very bland and breathy and it sounded like she was reading the lines, I think she tried too hard to sound authoratative. There were only a small few occasions where I liked how she delivered the lines.