When you ask a question be sure you follow the basic rules;
- Use correct grammar and make sure the reader can understand what you want answered.
"Best" is not the best word to use. To rephrase, which, if any, faction, is best for me to pick. Both are corrupt in there own way. Bhelen, if you played the Dwarf Noble, is a complete ass during the origin. He killed his own brother and tried to exile you. Based on this, I picked Harrowmont. At the end, when you get the sum of events that happend based on your actions, Harrowmont died soon after and caused the whole Dwarven city to go back to shit-town. Pick as you will because either way, I think the city and the game hate you. xD
Just to piss Bhelen off, i would go with Harrowmont.