I asked a question that turned out to have multiple correct answers. How do I pick between them to determine which to accept?
All of the answers were different. They were not the same answer given multiple times.
If the answers are different, but all correct, I would upvote all of the correct answers, and accept the one that I actually use.
If the answers are all the same, but came in at different times, I would accept the one that came in first, unless one answer was more clear or went into greater detail.
Pick the one that is better because it is
...or whatever criteria appeals to you that distinguishes one answer from the other. So far I have seen quite a lot of questions with similar answers, but there were always differences, and I would always have been able to find some tiny thing to help me pick one of them as my preferred answer.
First of all, vote! The voting buttons suggest:
Use them accordingly.
Secondly, there are no "shared first places" when it comes to accepting answers. So, pick the one that was most useful/helpful to you. This may differ from the criteria you laid out when asking the question. It's your choice.
Finally, if you feel like you still owe someone a reward for not picking their answer, you can always issue a bounty.