"Best" is not only subjective, but vague.
Best what?
Performance?
Beauty?
I have utmost respect and admiration for the folks who designed and built any of the very fast land speed vehicles (particularly streamliners). I find all these vehicles to be absolutely gorgeous, and am impressed with the design and execution in each
case, without exception.
Since land speed racing is (at least in theory) about going fast, my idea of "best" would be based on the vehicle's
performance. Yes, of course, its design affects its performance. My vote for most appropriate design for the (achieved)
performance would tend toward the Carbinite special. I am quite unhappy about its crash -- about 4 years ago -- , as I
had high hopes/expectations for this car to be the first wheel-driven vehicle to go 500 mph. Based on what I read, it
appeared to have been quite capable of this. Meanwhile, best wishes to Rob Freyvogel and his family as he continues to recover from his injuries.