in your discussion with lots of responses...

I haven't encounter situations such as yours yet since I'm still new. But in my opinion I would follow my feelings then in selecting the best one.

I read every single reply I get, but I don't have enough time or energy to reply to each one. I don't see a point in doing that, anyway. I don't always have something more to add to their response, so I will just leave it alone. I always read and rate the responses, though. If there are more than one responses that I think deserve best response, I will just choose one and move on. I don't give it too much of another thought because someone had to be chosen. I don't like leaving my discussions without a best response.