They are fine for the most part, as long as they are objective. There must be a definite answer. Using best
or good
is bad. Asking is something available, though is typically alright. However that is the precedent set by other sites, and our users votes will set a precedent for this site.
From the Stack Overflow FAQ:
To prevent your question from being flagged and possibly removed, avoid asking subjective questions where …
every answer is equally valid: “What’s your favorite ______?”
your answer is provided along with the question, and you expect more answers: “I use ______ for ______, what do you use?”
there is no actual problem to be solved: “I’m curious if other people feel like I do.”
we are being asked an open-ended, hypothetical question: “What if ______ happened?”
it is a rant disguised as a question: “______ sucks, am I right?”