Best landing spot: Miami Heat
All bias aside, as was the case for Damian Lillard, I firmly believe that the Miami Heat could very well be the best situation for Donovan Mitchell if the Cleveland Cavaliers do end up reversing courses by shopping him at the NBA Trade Deadline. But even beyond that, the Heat are very much going to remain in the conversation for Mitchell until he does sign that extension with the Cavs or is eventually traded elsewhere.
The Heat very much need a score-first star guard in the backcourt. For as talented of an offensive player as Tyler Herro is, he's not likely the answer to what the Heat needs. Mitchell is the dynamic star-level player who would fit ideally next to Jimmy Butler and Bam Adebayo. At this point in his career, that's exactly what Mitchell needs. He would benefit from landing in a situation where he could thrive by focusing on the offensive end of the floor.
That's exactly the situation that he would find himself in with the Heat. Miami would offer Mitchell the chance to excel as a first option while also giving him the foundation to win his first NBA championship.