Many questions on Programmers.SE are complex, behavior related and subjective ("My team lead is a psycho", "How to best teach coding", "Meetings in agile" etc). The nuances and depth of the questions and answers is what should define this site.
Some of these complex questions receives a bunch of easily digested, clever answers which gets upvoted quickly and then marked as accepted just as fast. That is fine on Stackoverflow, but programmers.SE are a completely different beast which deserves long and complex answers. I think there should be some way of actively encourage that. It's about increasing the quality of answers really.
A suggestion I thought about:
Don't allow questions to be marked answered until after a certain "grace time" (3-4 days) has passed.
Rationale: Questions left without an accepted answer for a number of days seems to shift. The easy/quick/clever answers loses ground to more thoughtful answers which bubbles to the top. That is a good thing. I assume it's because it takes time to digest the complexity and the hidden brilliance in some of the answers. Adding a grace time can perhaps help encourage that.