I know the Hallelujah chorus is the most well-known part of it, but the part that I crank to the high Heavens is "He shall purify." That showcases the full range of the choir in my opinion. Nevertheless, it's all glorious. There's a story that tells of Handel's assistant finding him crumpled on the floor, in tears, after he completed the Messiah. He claimed to have seen God. No wonder. There's just something stirring and powerful about that piece that cannot be matched.