Sonnet 18 (William Shakespeare)

Shall I compare thee to a summer’s day?
Thou art more lovely and more temperate:
Rough winds do shake the darling buds of May,
And summer’s lease hath all too short a date:
Sometime too hot the eye of heaven shines,
And often is his gold complexion dimm’d;
And every fair from fair sometime declines,
By chance or nature’s changing course untrimm’d;
But thy eternal summer shall not fade
Nor lose possession of that fair thou owest;
Nor shall Death brag thou wander’st in his shade,
When in eternal lines to time thou growest:
So long as men can breathe or eyes can see,
So long lives this, and this gives life to thee.

Perhaps the most famous of Shakespeare's sonnets, this one (typical Shakespearean sonnet: three quatrains and a couplet; ABAB CDCD EFEF GG). It is a comparison between a beloved and the summer. The lover triumphs over the season: "more lovely and more temperate"; the summer is shaken by "rough winds", and the sun is too hot.
The lover's beauty, unlike summer's, will not fade. In the ending couplet, the speaker explains the the poem will forever preserve the lover's beauty.
Though summer is compared negatively, many of its traits are still identified; it is the lesser of the two beauties.
"Rough winds do shake", "his gold complexion" are uses of personification; "the eye of heaven" is a metaphor for the sun. Apostrophe is also used throughout a poem, as the speaker is talking to a lover that is not present to respond.
This may be the most famous lyric poem of all time, and is therefore the most celebrated of all summer's poems.