"Spectre of the Gun" has always been one of my favorites (just watched it yet again), and the final act may be some of the best continuous 10 minutes in the series. The mind-meld sequence, intercut with the Earps' funeral march to the OK Corral, is mysterious and suspenseful. There's an interesting suggestion of unreality with the Earps, dull-eyed automatons walking that last mile amid wind, thunder, and lightning, and the mind-meld scenes with the coming storm almost minimal in weather effects.
YMMV.