Besides "Let All the World in Every Corner Sing," which has been set to many different tunes, a less well-known hymn by Herbert (at least in non-Anglican circles, it seems), is "Come, my Way, my Truth, my Life." Published in his work The Temple as "The Call," I like it for its play with the English language, as well as its meditative message.
Come, my Way, my Truth, my Life:
Such a way as gives us breath;
Such a truth as ends all strife,
Such a life as killeth death.
Come, my Light, my Feast, my Strength:
Such a light as shows a feast,
Such a feast as mends in length,
Such a strength as makes his guest.
Come, my Joy, my Love, my Heart:
Such a joy as none can move,
Such a love as none can part,
Such a heart as joys in love.
Maybe I'll have my church sing it soon. It would make people pay attention to what they're singing, hopefully, with its interesting phrases.
My other favorite poems from The Temple are "The Church Floor" and "Easter Wings," which would be less likely to be set as hymns, but are great poems. As to Donne, a great sonnet of his is #18, especially as I study for a Reformation comp.