What I do is picked the answer that most clearly and concisely answered the question, or I pick the answer that was most well-received. If everything is just an opinion, I roll virtual dice and assign a number from the dice to every answer that actually addressed the question.
I pick answers that fully address the question(s), ones that use reason and are thoughtful, clear, helpful, unique, informative, and well-written. If I'm asking a trivial question like, "on a scale from 1-10 how well can you dance?", then I'll pick an answer that mentioned something interesting (relevant to the question), or an answer that made me laugh.
I always give best answer, because I know people put time and work into what they write, and I want to make it worthwhile for them and acknowlege answers that stand out to me. People feel good about getting best answer and are encouraged by it, so that's why I do it. I give everyone who answers a +1 to show that I appreciate their answer, although, back when that meant an extra point it probably meant more.
I rarely give BA. I feel like when I do, I'm telling the other people who answered my question that their answer wasn't good enough (which is not the case). However, lately I've given a few, and I gave them because I thought the answers were genuine, mature and well thought out. Otherwise, I just don't bother. I hate it when people complain about QA's not giving BA. Like really, who gives a damn? Get your 10 points answering questions instead of complaining about not getting BA on an online forum.
If It answers the question best or it's funny and made me laugh. I usually forget to give BA
I pick the answer that helped me the most.
I only pick the ones that know what they are talking about. They show experience and they can give me some information about a possible outcome to my situation. They don't just tell me what I want to hear or what I already know but they provide a different perspective that I hadn't thought of before. I never let the up or down votes influence and I never let my own prejudices cloud the decision. I stopped choosing BA a long time ago though.
if it's well thought out and shows their opinion supported , not jsut a yes or no asnwer
It varies really... it could be because someone really opened up and shared something personal and moving, or because they came up with something really smart and funny, or because I simply agree with their answer.