Speculative rumor has Warriors or Heat as the only realistic option for Kevin Durant for his best chance at a ring.
A highly interesting report from The Oklahoman includes this passage from an undisclosed agent:
"So Golden State and Miami become the only real players," the agent said.
"It's too hard to justify a move to Los Angeles (Lakers) or New York because they are not close to winning. Houston's out."
Furthermore the unnamed source made a surprising prediction,
It's a decision that may already have been made.