My therapist and I are both men (and evidently I'm one of very few men answering this poll), but it's not really a factor for me in choosing someone. I've had both male and female therapists in the past who were terrible and who were great, and I don't think the things I value in a clinician (empathy, intellect, insight, etc) are at all dependent on gender. I can definitely understand others having a gender preference, though.

I think the fact that my therapist and I are both queer men has more of an impact than just the fact that he's a man. There's a downside since it makes it more likely that our social circles will overlap, but it also means we have many more cultural reference points in common.