Past performance (have they sold places similar to ours? For how much? How fast?)
Recommendations from past clients
Honesty - tell it like it is, from where home should be priced to what we need to do to our home to get it sold
Actually "sells" home - attends showings
We chose our last agent through a flier she mailed touting her success selling another unit in our building for a great price. After interviewing several realtors, and talking to her past client in our building, we chose her. She was aggressive (sometimes even abrasive) but she was honest about her process (she wouldn't take us on unless we did a lot of decluttering and fixes, and was specific about us having our place spotless every day with fresh flowers) and sold for a great price within our timeframe. I'd use her again.