Assuming you're in the States...
Your next of kin should automatically become executor. Their expenses have first claim to the estate (remains, death certificate, service, court and other fees, etc.), creditors follow, then heirs. A will may speed things up in probate, in some states setting up a trust would also speed things up. The only reason I would bother with a will would be if I were to assign a different executor than next of kin. The executor needs to be able to pay some things out of pocket until probate.
Of course do your own research. This came from my recent research to determine whether it was worth the effort or expense to leave a will.