Detroit

Future!Dean tells Dean that Sam was in Detroit when he gave Lucifer permission to possess him^{5.04 The End}

Lucifer informs Sam that he will eventually say yes to him and become his vessel ^{5.10 Abandon All Hope}
Sam later becomes his vessel, but he eventually regains control and throws himself, Lucifer and Michel in the Cage^{5.22 Swan Song}

Notes

5.04 The End and 5.22 Swan Song clearly illustrated two separate outcomes.

Major Similarities:

• Sam assented to Lucifer, and he did so in Detriot.
• The spread of the Croatoan Virus occurred.
• Bobby Singer died; however this wasn't permanent in 5.22 Swan Song because Castiel resurrected him.

Major Difference:

• The amount of humans infected with the Croatoan Virus.
• Samifer told Dean that he'll see him in fives years; we learn in 5.22 Swan Song that this is incorrect because the year is still 2010 when they meet agian.
• Dean and Samifer don't meet at the garden.