I love the sonnet, both to read and to write. Sometimes one seems particularly beautiful or really makes me think. I'll share one at a time as the mood takes me. Here's one by John Donne (1573-1631). I love how this reads like someone speaking, but on inspection keeps perfectly to the standard metric and rhyme of a sonnet. This is characteristic of many of my favorites.
At the round earth's imagin'd corners, blow
Your trumpets, Angels, and arise, arise
From death, you numberless infinities
Of souls, and to your scattered bodies go,
All whom the flood did, and fire shall o'erthrow,
All whom war, dearth, age, agues, tyrannies,
Despair, law, chance, hath slain, and you whose eyes,
Shall behold God, and never taste death's woe.
But let them sleep, Lord, and me mourn a space,
For, if above all these, my sins abound,
'Tis late to ask abundance of thy grace,
When we are there; here on this lowly ground,
Teach me how to repent; for that's as good
As if thou hadst seal'd my pardon, with thy blood.