When I'm browsing around the trilogy, my policy is to only upvote questions/answers that I feel are underrated, and I only downvote answers that I feel are overrated.
For instance if I see a humorous response to a question, and it has less than 2 or 3 upvotes, I'll most likely vote it up. If that exact same answer had 20 upvotes, I probably wouldn't. If it had 200 votes, I'd most likely vote it down. This goes for any answers, not just humorous ones. I assign everything I read a value I feel it should have. I then vote either up or down to help move the rating to where I feel it needs to be.
My policy is as follows: Any answer that makes any effort to be helpful, deserves at least 1 upvote. Even if the answer is wrong (unless its blatantly wrong). If it's a few paragraphs and kinda goes above and beyond, it deserves 5 or 6 upvotes. If it really goes the extra mile to be completely thorough, and it seems the author did special research for the answer, that deserves more than 10. If an answer is really long and really thorough, but it doesn't answer the question in any way (I've seen this a lot), it deserves one upvote at the most. I hate it when people do that. Blatant rep mining. Unless they post an apology or something explaining how they mis-interpreted the question, I'll most likely vote it down (unless I asked the question, in which I never downvote unless they're spamming or something)
When it comes to questions, anything thats not "send me the codez" or so "localized" to the asker's specefic problem, should at least be 1, maybe 2 at the most. If the question brings up a really interesting "corner case", and it seems the OP did a lot of research beforehand, it should be a 5 or 6. Only the really thought provoking question should be a 10 or more.
It seems to me that most people here don't do it that way. They vote on questions and answers based solely on their own "vacuumed" opinion. If they like the post, they'll vote it up, regardless of how many people have already done so. Because of this, I've noticed questions that cover broad topics, (which have the most views), seem to get answers with the most upvotes, regardless of the quality of answers therein.
Is this be how it should be? Or should we encourage people to vote with a system such as mine?
edit:
Lets say you come across an answer that was a one liner, was only marginally helpful, and had 30 upvotes. Does this person deserve 300 rep points for this answer? Is that fair that that person gets such a bump, while most other people post much better answers all the time without even getting 2 or 3 upvotes? In this case is it "ethical" to downvote the overrated answer? I guess judging by the reception of this thread, it is seen an unethical. But why?